Check this page at Adobe's site for short videos on some of the new features!
New Mercury Playback Engine
The Mercury Playback Engine is 64-bit native, optimized for operating systems, multicore processors, and NVIDIA. It promises improved performance when working on complex times, and mix and match AVCHD, P2, XDCAM, RED, and DSLR camera formats freely in the timeline, without rendering.
“I was among the first Final Cut Pro users ever, but my Final Cut Pro days are over. Adobe Premiere Pro CS5 is stellar because it offers the 64-bit Mercury Playback Engine, giving me the ability to work in real time with 4K RED files—I literally couldn’t pay enough money for that.”
- Tim Walton, documentary filmmaker and editor for Sacramento, California PBS affiliate KVIE
Native support for a variety of tapeless formats added
In addition to Canon and Nikon DSLR support, CS5 adds new support for XDCAM HD 50, AVCCAM, DPX, and AVC-Intra, as well as enhanced RED R3D support. Premiere already supports P2, XDCAM EX and HD, and AVCHD. Premiere can also now take advantage of new logging options for tapeless cameras in Adobe OnLocation.
Roundtrip with Final Cut Pro, Avid Media Composer and Digidesign Pro Tools
Premiere Pro CS5 supports roundtrip editing between Apple Final Cut Pro, Avid Media Composer or Digidesign Pro Tools software.
The open architecture of Premiere Pro CS5 allows it to be extended to work within custom infrastructures. Adobe Premiere Pro CS5 is extensible using panels created in Adobe Flash Professional, enabling broadcast and film companies to use Adobe Premiere Pro in tightly integrated workflows, including integration with asset management and file transfer systems, as well as with newsroom systems such as ENPS. [What does that mean exactly? I don't know! I hate press releases! But it sounds like you can write your own widgets in Flash that will control Premiere. That's what it sounds like to me!]
CS5 is expected to ship in 30 days.
Adobe: Premiere CS5