Conroe is the brand new and soon to be released Intel CPU architecture.
Performance is MUCH better than previous Intel options.
I cannot find any Conroe CPUs for sale today, but should be available by next week.
The impact of Conroe on the market can best be shown as follows:
AMD drops desktop processor prices by 47% Tom's 07/23/06http://www.tgdaily.com/2006/07/23/amd_slashes_desktop_processor_prices/
If you can wait a couple of weeks for the market to better sort itself out, I believe you will win no matter which brand you buy.