If you're talking about DDR2, it can be faster, but the thing is it needs to run at very high speeds to compensate for it's latency. It looks like even Intel may be backing off from pushing it as much.
Yes, Intel will have dual-core, but if they use HyperThreading, I hear that can cause trouble. AMD will also have dual-core which should be available this summer.
I'm not sure if Intel is going to a 1600MHz FSB. They've only recently gone to a 1066MHz FSB with the 925XE chipset, which uses the DDR2 only.
Furthermore, the only Intel-based SLI configuration is an Alienware exclusive and uses a different means of implementation than the nVidia nForce 4. Secondly, while there are Intel-based motherboards available, they're for the Xeon, which uses a different socket than the Pentiums.
Intel is moving toward making the core of the Pentium M the core of the Pentium D, which replaces the P4. It's a much more efficient design and even at low clock speeds, it's an awesome piece of work.
The issue here is that, right now, this stuff isn't available. While I haven't heard anything yet, Intel is known to change sockets rather often, whereas AMD doesn't. You could be talking a difference of changing to a new motherboard (and possibly new RAM and PSU---depending on what else goes with it) vs a BIOS update.
Will there be SLI for Intel? I'd find it hard to believe it wouldn't be. The nForce 5 that's coming up and ATi's Intel chipset are looking to be pretty nice. But without any reviews available at the moment, it's hard to say how things pan out.
Basically, if you want SLI now, you have to go with an AMD system. If you're willing to hang loose, you should have a better selection between AMD and Intel.
http://www.theregister.co.uk/2005/03/10/nvidia_nforce_intel/
Well, the Reg does say we could see an Intel SLI here within a month, but they are a Tabloid, so I'd take the info with a few grains of salt. Additionally, while nVidia doesn't produce crap, you need to be aware that if you go that route, you'll be an early adopter. There's always the higher chance of issues, not to mention that SLI does have limitations which is more than likely not limited to AMD's side of the table.