the Demise of the Low noise sensor?

Canon had always been the noise king. From 350D all to the 450D the sensor was a gem.

you could take 30 minute exposures without any Dark frame substraction, and yet get lovely clean shots.
Unfortunately the 50D and 500D are a demise from that philosophy.
You have 15MP crammed into APS-C sensor.

Clean star trails are a thing of the past (look at flickr camera finder if you do not believe me).
So is it end of the canon road for people like me who dig starlight photography?
Or do we have to spend 3 times as much and get the full frames now.

Or maybe canon will see sense and we will see the return of the 12MP sensor in some form.
Any ideas?
--
Tanveer
My galleries - http://tanveer.smugmug.com ,
My site : http://www.tanveer.in/drupal
My Photoblog : http://www.tanveer.in/photoblog