Does the copy and paste functionality work within apps like Facebook and Twitter?
In some places yes, some places no. For example, on the news feed, it doesn't work. But if you make a comment in a box you can copy/paste there. It seems that if you have a text box, it works. Another example. If you open a calender entry you can't copy/paste, but if you edit that calender entry, you can copy/paste there. However there are some places w/o a text box you can copy/paste. In IE, I can copy text and then paste it into an office document, or email, etc.
edit: sorry saw the twitter part of the question. In rowi, birdsong and twitt you can't copy directly from a tweet, but if you retweet, which brings up a text box, you can from there. Another interesting observation. I can copy from IE, but not from surfcube or 7 tab browser pro...