It depends on a couple of things..
1) Is your plan a legacy plan that you wont want to give up?
2) Do you like your phone, and dont mind waiting until late 2010?
If you think yes on #1, then consider going with the TP2, as alot of people think legacy plans will be locked out from new sweet toys once they introduce 4G PPC's.
If you think yes on #2 and you dont mind giving up your legacy plan (if you have one), there are big things in the works. You have the recent snapdragon chipset, which will make it to alot of phones this year, there is already talk about a dualcore snapdragon that will hit late 10 early 11. Plus M$ has been working with nVidia and their new Tegra2 chipset(Which is a pretty rediculous chip). To put it in a simple phrase, I'm already over the whole HD2 Hype
All said, I really like the Palm Pro. Everything is nicely integrated and works right out of the box, great battery life for a PPC, and its a remarkably snappy phone for the time of release. All in all, its a phone I can reccomend my friends if theyre interested in trying WM and dont want to break the bank.
Personally, If I had to pick between the Palm Pro, or the original Touch Pro, I would have chosen the Palm Pro for sure