All I can say is WOOOOOH YEAH.
There is a bunch of stuff in here that is brilliant for Tablet PC users, and also for other stuff as well. Service Pack 2 is basically an upgrade to Tablet PC 2005. Free upgrade! :o)
The new writing input panel context is incredible – now it shows up whenever you come across a input field, instead of you having to manually open and close it. Also, character recognition is definatly better – not to mention the fact that the writing pad will translate your handwriting as you write so you can see if it's correct or not as you do it.
I could go on about the new bits and pieces – but here are some links to articles that explain it better:
Windows XP Service Pack 2: How it affects Tablet PC Edition
Windows XP Tablet PC Edition 2005: Tools to Use with Your Tablet PC
Windows XP Tablet PC Edition 2005: New Ways to Interact with Your Tablet PC
The other big thing I found useful was the move to the Microsoft Bluetooth stack. Before this came along, I was running the Toshiba Bluetooth stack, which worked fine for most things – however did not get along very well with my new Nokia 6230.
I uninstalled the Toshiba version (as described here) and installed SP2 and now, my Nokia phone talks happily to my PC.
So all in all – I'd like to say WELL DONE to Miscrosoft for once, it's been a pleasure working with you.