Hi,
I guess you have to be patient. I have a 400d, the 450d doesnt make the 400d a bad camera, it's still the same 400d.
In two years time when i buy a new DSLR maybe, definately it will be better than my 400d, but if i have cared for my 400d it will still be a good camera.
It's exciting for people buying a camera at the moment that they can get this but maybe i will have a 650d in a few years time, you just have to learn to be patient and use what you have
One 5 minute light frame of say the horsehead on any DSLR looks horrible. But 20 frames stacked and dark framed on any DSLR looks bloody great.
Paul