From my understanding, the limitation is so that the natural progression of the conversation is preserved, and people tend to think a little harder about what they say when they know they can't go back and edit it.
It holds people accountable.
Blogs on the other hand I feel should be editable at any time since some blogs organize content differently and thus require a different approach.
I doubt we're going to see any significant changes to the length of time you can edit after posting.
I'm kinda new at this, so you'll have to wait until the other navs chime in to give you a definite answer on the blog editing...
Edited by Joseph, 16 January 2009 - 04:47 AM.
For the sake of editing...