Looking rugged and road warrior ready, the new P900 looks sexier and excels with subtle improvements inside the box. Here's a couple of them here. One with the removable keypad on and one naked. The biggest obvious improvement is the move to 65000 colors which is another eye-pleaser. There's a really good in depth review of the P900 at the Register. To my envy, the P900 is sleeker, has louder rings, better reception, longer battery life, and *outstanding* T9 text input.
Even though you don't see many P800s in the States, to my surprise, over a million P800s have been sold and the P800 is the biggest selling single PDA model on the planet. If that's true, there will indeed be a software platform there (Symbian 7 UIQ) to work with and thus plenty of good software. I've noticed a big uptick in available software lately. Luckily for us P800 owners, the platform remains the same so we can benefit from the emerging popularity of this polished upgrade.