Agreed. I know there are some issues with people who uses Twitter via SMS but I figured by now they would found an intuitive way to ignore URL's in Tweets.

metadata such as urls do not belong inside the message body when they can be attached to a separate field per tweet.

this can even be expanded; get other useful data such as gps location or hashtags out of the body and into a metadata field.

I often recieve tweets via SMS, and then just type the bit.ly link in, because that's easier than opening up the page of whoever tweeted it and clicking the link.

I think it's an incremental improvement. It won't make or break bit.ly, but a hundred such improvements will make it a success.