Yup, it's released. Been a busy day though so I haven't had a chance to look too deeply in. You can check out the discussion of it over on Digital Photography Review, where they highlight the features that are most likely to affect photographers. There's also the 61 minute launch event, and the full CS5 press release.
Pricing and Availability:
Adobe Photoshop CS5 and CS5 Extended are scheduled to ship within 30 days with availability through Adobe Authorized Resellers, the Adobe Store and Adobe Direct Sales. Estimated street price for Adobe Photoshop CS5 is US$699 and US$999 for Photoshop CS5 Extended. Upgrade pricing and volume licensing are available.