Configured my new Blackberry 8830 yesterday. Very impressed. Syncs with Outlook and Hotmail, and renders SharePoint pages.
Would recommend these apps:
RSS reader
Viigo Browser
Opera Mini
Google Maps
USA Today
Mobile InfoSpace
Find It! Fox
Business Mobile ESPN
Mobile WorldMate Live - if you travel a lot (free or upgrade)
Tellme
Beyond 411 or Berry 411 - Quick Google like search