I have been following the new Intel line pretty closely so let me try to clarify.
The newest current dual core out from Intel out now for the desktop is the 9xx series. These are still P4 based chips but on 65nm. Not worth a purchase IMO.
Core Duo (aka Yonah) has just recently been released for the mobile line. It is a dual core mobile processor based on Intel's new architecture. While these chips are very impressive there is currently no desktop boards out for them yet (it's looking like the AOpen board will be here in March).
Conroe is coming in June/July time frame. It is also a dual core CPU based on the new architecture. This chip is looking to be very impressive, and like what has been said, could very well give the lead back to Intel. Conroe will have initial clocks of ~1.9Ghz to ~2.7Ghz depending on model number, and an XE at 3.33Ghz has also been announced.
Memron will also be coming out probably after Conroe maybe fall time, not sure. This will simply be an updated mobile Core Duo with 64-bit.
On the other side. AMD's new socket and CPU's are coming out I believe this summer as will, AM2. These chips will use DDR2 memory and have higher HTT speeds.
My advice would be to wait until this summer if you can, see how Conroe and AM2 compare to each other and pick the best one.
BTW, if you still end up not feeling comfortable building yourself when you are ready to buy, sites like Monarchcomputers will assemble parts you pick out for you.