A cabal of tinkers have managed to get root access on the G1 using telnetd. Now, whether or not that constitutes “jailbreaking” (which is an awkward word to use considering Android is supposed to be an open source operating system from the get-go) or something a little less dramatic is another matter.
Or, to quote a Gizmodo commenter:
This reminds me of the Spongebob episode where they steal a balloon on free balloon day.
I think that says it all.
via Slashdot
You would be right if you were talking about Android, but you are talking about the G1. Android is completely open, but the G1 is closed tight as hell. Tmobile doesnt want a lot of things accessed (to save them bw im guessing) so this is actually closer to the jailbreak you are thinking of.