The first solid indication of an announcement was Engadget's first look at the Palm Treo 700w, published on Thursday. This was followed an announcement from Palm investor relations that Palm, Microsoft, and Verizon Wireless would make a joint announcement on Monday, September 26 at 12:00 noon EDT. This press release came out at 4:05pm on Friday, minutes after the close of the regular trading on the NASDAQ.
Palm's advisory was followed by an article in The Wall Street Journal reporting that Palm is set to use Microsoft code on Treo Phones. In my opinion there's a big difference between speculation about a Windows Mobile-based Treo by gadget-related blogs is less significant than a news article in publications like the Wall Street Journal [ Subscription required. ].
I'm very optimistic about the market prospects for a Windows Mobile-based Treo. I think that Palm would not be releasing it if it didn't meet their high user-experience standards. The Windows Mobile platform has been in desperate need of a manufacturer like Palm who are committed to adding value instead of just rolling out a compatible handset.
As for the future of Treo's based on the PalmOS, we'll have to wait and see. I don't think that Palm will ever integrate Treo functionality into the PalmOS Cobalt operating system, but subsequent PalmOS implementations based on Linux resulting from PalmSource's acquisition of China MobileSoft may be more to their liking. My experience with the Treo 650 is that there are times when it's really obvious that the phone could use an operating system capable of multi-tasking, and PalmOS based on a Linux kernel may be a good solution.