The official release of iBooks is available now for download, get it here. In my quick look, it’s super smooth. Definitely blows GoodReader out of the water for PDF support. Animations are smooth, and effective. Like the iPad version, the application has hardware control over the brightness (cheaters). Chapter selection on PDFs does not appear to work, it goes by page instead. Bookmark syncing, notes, highlights and searches (on words) are all fully functional…, except in PDFs. I can’t seem to get it to work there. Don’t forget that Winnie-the-Pooh is free!

Also pouring in are iOS 4 enabled applications. Many simply getting fast app switching (which is just like multitasking for apps that don’t “do anything” like WordPress), but others getting legitimate multitasking capability as well. Engadget has a preliminary list here. Ars Technica has a massive, seven page epic on the new operating system for those that have some free time.