Brand new MySpace CEO Owen Van Natta started things off Monday with his first day on the job. He was joined by new COO and former AOL exec Mike Jones and new chief product officer and former Sling Media exec Jason Hirschhorn. Down in Los Angeles at the AlwaysOn OnHollywood conference, Boomtown ran smack into Huff Post mastermind Arianna Huffington, who extolled the virtues and abilities of new managing editor Jai Singh, former editor-in-chief of CNET Networks. At AOL, in preparation for spinning off the Time Warner (TWX) Online unit, new CEO Tim Armstrong began appointing new senior execs and spinning off existing ones. Platform-A president and former Yahoo (YHOO) sales exec Greg Coleman, who joined the AOL team in February, is leaving the company, to be replaced by Jeff Levick, who is leaving Google (GOOG)–where he had a close relationship with Armstrong. CFO Nisha Kumar is also leaving AOL, and a search is underway for her replacement. MediaMemo has more on Time Warner’s decision to spin off AOL. A number of Flickr engineers were laid off Wednesday, but Chief Architect Cal Henderson has left the company of his own accord and is working on a stealth start-up with Flickr co-founder Stewart Butterfield. Last, but not least, one of the voices covering the digital scene has found a new gig. Owen Thomas, self-described “scourge of [Silicon] Valley,” is leaving Valleywag to head up GE (GE) unit NBC Universal’s new “Bay Area” Web site, whose motto is “Locals Only.” He’ll be replaced by fresh-faced Ryan Tate, recently the night editor for Gawker. Both reporters talked to BoomTown on Friday about the changes.

MediaMemo wrote on Monday about Condé Nast shutting down Portfolio–both the print magazine and the accompanying Web site. On a cautionary note, MM outlined the reasons why Portfolio’s business magazine peers should not celebrate the loss of a competitor, even (or especially) during tough economic times. Is the meteoric ascension of Twitter flattening out? According to a Nielsen Online study, 60 percent of Twitter’s users leave after a month. This was met with a lot of skepticism so Nielsen ran the numbers again with the same results–and this time it’s sticking with them. MediaMemo also had an explanation for why the long-awaited deal between Disney (DIS) and Hulu took months and months and millions of dollars to finally come together. Digital Daily had more on that story.

Digital Daily also had more info on the ever-evolving Palm (PALM) Pre story. First, a rumor that Palm plans to launch the handset on June 7–which would be crazy, given the fact that June 8 is both the first day of Apple’s (AAPL) Worldwide Developers Conference and the day that those in the know expect the next-generation iPhone to drop. Then, there’s an assertion by Collins Stewart analyst Ashok Kumar based on supply chain research that Palm has greatly reduced its production numbers. Time will have to tell, though, because Palm certainly isn’t talking yet. Of course, things could be worse. Dell (DELL) hasn’t even solidified plans for its rumored smartphone, and already, no one really cares.

Dell’s new Adamo laptop and Studio One 19 desktop aren’t causing much excitement either. In this week’s Personal Technology column, Walt Mossberg reports that although both machines look good and function well, neither is groundbreaking. In Mossberg’s Mailbox, Walt answered readers’ questions about improving performance on a PC, using peripheral devices with an iPhone and installing Apple’s OS X on a Windows machine. And in this week’s Mossberg Solution, Katie Boehret tested three apps from the iTunes App Store that make it possible for the iPod touch to function like an iPhone.

More next week.

Safe to say that the mood of last week–with its anticipation of change–is a distant memory. A different kind of anticipation permeated the tech and online media industries, one more reminiscent of April 2001. There was news all around of layoffs, pending layoffs, bankruptcies and stock dives.

To wit:

Digital Daily offered up a body count of companies in the tech sector that have been beaten into whimpering submission. Nortel (NT), once a telecom high-flyer, lost $3.4 billion in Q3. The company announced plans to lay off five percent of its workforce–including some high-ranking executives–eliminating 2,500 positions. Other high-ranking execs are taking part in the econalypse too, notably Kevin Kettler, Dell’s (DELL) chief technology officer. A week after the computer maker began offering workers voluntary separation plans, Kettler decided to take the company up on it. No word on how many followed suit. Other victims of the gloomy economy are Circuit City (CC), which declared bankruptcy this week, and Intel (INTC), which faced “sharply lower revenue.”

Media Memo presented a handy index of actual online advertising sales results (courtesy of Jupiter Media) and noted that the ad slowdown has hit Google (GOOG), too. Nick Denton, Gawker Media publisher, folded Valleywag into Gawker.com, the flagship blog of the media empire and, in an ironically appropriate move, put Consumerist up for sale. Denton, doom-mongerer of the econalypse, would surely appreciate the following layoff roll call: Condé Net and Time Inc., not once, but twice. No, wait. Three times.

BoomTown was on a Yahoo (YHOO) roll this week, writing about the company’s upcoming layoffs and its stock plunge. Just to squash rumors: Jerry Yang will not be laid off. Social media, mainly Twitter, became a hot topic this week in terms of its effect on the PR industry, and BoomTown had something to say about it. Also noted was the good humor of Mobuzz video, which made a plea to its users to donate five euros apiece to keep it afloat. And in case you were wondering what makes BoomTown impatient, the main two things this week were Microsoft’s (MSFT) continuing failure to find a head for its digital business and Yahoo/AOL’s failure to make anything happen in the ongoing yawn-fest of a nonacquisition.

In Personal Technology, Walt Mossberg gave the lowdown on Wi-Fi for your car, and in Mossberg’s Mailbox discussed disabling Wi-Fi on a laptop. In The Mossberg Solution, Katherine Boehret reviewed the Flip MinoHD, the latest addition to the Flip family, and its first foray into hi-def.