Glass!
I agree with Scott's recommendation! Sell the cheaper glass to help fund the high-end glass and then never look back.
Use bing.com (before it dies on 7/30) and save around $75 on the following:
Canon 24-70 f2.8 L
B&H
Retail: $1309
With Bing: $1,282
Abes of Main: (9/10 on resellerratings)
Retail: $1,278.00
With Bing: $1,252
both offer free shipping on this lens!
50mm f/1.4
B&H
Retail: $345
With Bing: $338
Abes of Main: (9/10 on resellerratings)
Retail: $334.00
With Bing: $327
Save even bigger when buying a body using bing! Do you really need two bodies? Sell the 20D while you still can and if you don't need a second camera.. sell the 40D and get a canon 7D for only $1408 (vs. $1600)