I would give the 7D some time to get the bugs worked out. I test drove one for two weeks and was not overly impressed enough to justify the cost increase over the 50D. Our local shops pulled them due to proplems, not a good sign. I know its alot more expensive but the 5D is a much better choice than the 7D.
The high iso noise really isnt an issue if you buy good glass. The focus goodies are great but dont really help enough to make a difference. Its much easier to put money into fast glass and good lighting. Even with the additional features you will still need both.

Don