Twitter's new terms of service restricts the use of tweets to the determent of the twitter ecosystem.
Specifically I feel overly constrained by:
4. You will not attempt or encourage others to:
"use or access the Twitter API to aggregate, cache (except as part of a Tweet), or store place and other geographic location information"
I was just about to archive the contents of my tweetstream for analysis of various sorts, including (eventually) location.
Your Client must use the Twitter API as the sole source for features that are substantially similar to functionality offered by Twitter. Some examples include trending topics, who to follow, and suggested user lists.
I find that to be crossing the line. If someone making a better source of trending topics, and I have a twitter client, I would want to pull information from that service to enhance the experience of my twitter client.
5. E. You may not use Twitter Content or other data collected from end users of your Client to create or maintain a separate status update or social network database or service.
This sounds like it kills any cross-posting app. If my app collects a status update and posts it to two networks, twitter is now trying to kill that. Its these cross-posting apps that will help the migration from twitter to new status/microblog networks.
Its time to get more serious about moving to a federated system.