You still cannot release a twitter client that doesn't get maxed at 100,000 users. Why bother implementing ideas when it will probably meet with the same problem due to our success.
Frankly, it should be a lot more about client apps and new ways to use the information in a personal manner instead of creating an API that looks for all the world like something I can use to automate my support staff on twitter and fire a bunch of people.
Twitter is so afraid of losing their users that it's becoming a self-fulfilling prophecy.