What specifically do you lose upgrading to 2.1 jailbroken?

[ardpbub]

I have been reading all the new posts about upgrading to 2.1 when already jailbroken and I am confused. Everyone says the phone will still be "unlocked" but no longer "jailbroken." What is the difference?

Thanks to all.

[nomar383]

Please do not discuss pirated app store apps here.