I wonder if the 8820 (supposedly being released July 30th), if its OS will be compatible with an 8800? According to RIM, the 8820 has both the A2DP and the new media player that's got me wishing I had a Curve. Also compatible with 32GB microSDHC!

"- Multimedia - The BlackBerry 8820 supports the Bluetooth stereo audio profile (A2DP/AVRCP) and comes with the most recent BlackBerry media player refinements, allowing users to play music and search by simply typing the title, genre, artist or album name. Videos can also be played in full screen mode.

- microSD / microSDHC Expansion Memory - The BlackBerry 8820 includes a microSD expansion memory slot that can support both microSD (up to 2GB) and microSDHC (4GB to 32GB) memory cards. 4GB memory cards are available today, and 8GB cards are expected to be available later this year."

Source: Research In Motion - RIM Announces the BlackBerry 8820 Smartphone

No, you can not upgrade 8800 with OS for 8820.