The T-Mobile Sidekick data loss disaster is still going on and T-Mobile has not officially updated us on the situation yet. The last statement is from Friday and supposedly a new update on the loss of private data on Sidekick phones is due today.
Hiptop3 reports about Sidekick users getting discounted upgrades to a T-Mobile G1 or MyTouch 3G to stay with T-Mobile.
Others managed to get out of their contract early without penalty. Others report that they were not offered anything.
There is no official guidance on this. I assume it depends who you reach on the phone at the T-Mobile customer support center and your people skills. T-Mobile may also change the policy on how they handle unhappy Sidekick users.

It will be interesting to see how T-Mobile and Microsoft handle the situation moving forward. It is a huge issue and they need to do some serious damage control if the Sidekick phone is going to stay.