Im definately sticking to 1Mb/1.5Mb.
Mainly because im in a nice little area full of small villages and towns, with hardly any internet usage, meaning i get uber low pings (bbc.co.uk@10ms, 24/7) my downloading goes at 120kB/s nearly all of the time, and im hoping that streaming video becomes more prominant as time goes on.
Im hopeful (probably in vain) that upload speeds get a 50% speed boost too, 384kbs isnt a huge jump, but would enable me to host sven co-op servers with 10-12 people