Dieter has reported over at our sister site WMExperts that just like last year, another Palm smartphone has been outed at a Microsoft Keynote. Last year it was the Palm Treo 800w that showed up on the video screen. This year, what "appears to be" the Sprint Treo Pro, was shown on the video screen while Microsoft was showing Internet Explorer 6's flash support.
We know that IE6 Mobile isn't going to be made available on current devices, but requires a completely new ROM, plus a decent amount of power on whichever devices it lands.
Dieter points out that:
"We already have seen screenshots of Internet Mobile 6 leaked here on WMExperts and also seen speed tests from an unreleased Sprint Treo indicating the browser was Internet Explorer 6. So sure, it's entirely possible that we are looking at a GSM Treo Pro running Internet Mobile 6 with a customized ROM. But why go through all the trouble of creating a custom ROM when there's a perfect explanation of what we have here?"
So it seems very likely that the photo here is of a Sprint Treo Pro.