If you want a decent upgrade to the 50D then you need to jump up to the 7D these days.
The X0D range has been cheapened with the most recent model, 20D, 30D, 40D and 50D were all magnesium bodies and aimed at the semi pro market, the 60D by comparison feels a bit like a toy
Unless there is a feature on a new body that you are keen to exploit or another compelling reason for you to upgrade then I would save your money or invest it elsewhere.
People fixate on gear a lot in photography (I know I certainly did) and in many cases spending money on new gear will give very marginal returns compared to what would be achieved if the money were invested in a training course or instructional video of some kind.
I have many friends who have bought SLR's over the last few years and whenever one of them asks about getting an upgrade "so they can take better pictures" I take a look at their camera, see it set in green box mode or P and tell them not to bother with the upgrade.
Its the bit between your ears that makes the photo, spending money on a training course or training material would yield far better photos for most people than a camera upgrade would do.