“Based on our channel checks, the iPhone remains the best selling device at AT&T with both the new $200/$300 iPhone 3GS and $100 legacy iPhone selling very well,” Piper Jaffary analyst Gene Munster said in a research note today.

“In July, our checks had indicated store managers were strongly recommending the legacy iPhone,” Munster notes, “as we believe this was partially driven by store representatives hoping to make the sale with the 3GS stocked out combined with efforts to reduce existing inventory levels of the legacy iPhone. However, in August, our checks indicate store managers are increasingly recommending the 3GS, and we believe this is driven by improved availability of the 3GS at most AT&T stores.”

Munster summarizes: “Overall, the iPhone remains the best selling device and our August checks indicate the iPhone took share from BlackBerry, the Nokia E71x, and most other competitor products. Finally, in our checks at Best Buy, store managers indicated the iPhone was their best selling device with stores selling out of stock as soon as they received the Apple smartphones.”

A bullish assessment, with an even more bullish conclusion: Munster says he expects Apple (AAPL) to ship seven million iPhones in the quarter. If that’s truly the case, Apple should have no trouble beating Wall Street’s expectations for its current quarter despite the gloomy economy.

One last point worth noting here: Munster is not bullish on Apple’s event tomorrow. He describes it as a “non-event,” though he seems convinced Steve Jobs will host it. “We expect Steve Jobs to introduce a new iPod lineup with a new iPod touch, new nanos, and a new classic, with cameras in the new models,” he notes. “We expect the stock to trade off on a lack of surprising announcements.”

380,000 Kindles sold. That’s double Mahaney’s May prediction. And it’s an important number historically. “In its first year, that’s exactly how many iPods were sold,” Mahaney wrote. “Turns out the Kindle is becoming the iPod of the book world.”

But is it really? And on what sort of data is that pronouncement based? Amazon (AMZN) itself has disclosed no actual sales data for the Kindle. The company said only that the selection of titles available for the device has jumped 67 percent since its launch. Surely it’s impossible to extrapolate sales of 380,000 from that figure alone. So on what other data is Mahaney relying here? Just this, apparently:

1. An anonymous source recently told TechCrunch that Amazon has shipped 240,000 Kindles. That’s shipped, not sold.
2. Kindle tops Amazon’s Bestsellers in Electronics list
3. Kindle has more than 4,000 customer reviews, quite a few of them positive.

Not exactly an abundance of hard data, is it? Which is not to say that the Kindle isn’t well on its way to becoming the iPod of the book world, just that we won’t know for certain until Amazon tells us with hard sales figures.