Seen her 4 times now, including this tour - always very entertaining. In this current show, the best segment for me by a long, long way is the Confide/Cowboy Style/Too Far sequence, but then that's the period I like best, and it's rare for her to do anything at all from Impossible Princess - this time she does 3! (Those 2 plus Dreams).
I seem to get lucky - in 2005 I saw her in London about 2 weeks before she was diagnosed and pulled the rest of the tour. This time, I saw her last week in London so again just missed the cancellations. Jenna, it's tough BUT they will almost certainly reschedule your show so hang on to your ticket and look forward to seeing a great performance.
Also, E4 are going to be re-showing Saturday's C4 broadcast of the Melbourne show from December - it's pretty much the whole show - so keep an eye on the schedules.