It depends where you are and what non-local packages you have.
There is a small handful of channels added in the SD local range, which anybody should get.
Some normal specialty channels should be HD, like YTV, Lifetime, normal Discovery, and a few others.
At least for my Ontario locals, CHCH and TVO are now available in HD.
But I got upgraded to X-Ku, a 605 and a 600, for the turn on and couple months preview of the added G1 channels. You might not gain much now upgrading to a G1 capable system.