As mentioned earlier, I got the latest system update for my G1. Now running firmware 1.5, aka Cupcake. Here are some of my first impressions:
* More polished: transition in between menus and graphics are a bit softer, dynamic and feels more elegant
* Better UI: onscreen keyboard w/ auto-correct feature; Gmail's most used feature are readily below each email, everything just feels a bit more convenient with the update
* Onscreen Keyboard not as robust as iPhone's but the word suggestion is VERY handy!
* Chrome/Browser much improved, very smooth and URL bar/search makes good suggestions like desktop Google toolbar; still unable to edit blogspot posts however and can't handle Lotus notes webmail (same fate as iPhone's mobile safari)
* Camcorder: simple operation, with an on screen record/stop button; two video quality (MMS is low, SD storage is High); YES, it supports upload to YouTube (via YouTube app)
* General performance feels a bit faster all around
* I have not played with this update long enough to comment on battery life
It definitely feels like this update has iron'd out a lot of kink; I think I am falling in love with my G1 all over again.