A good way to compare the mobile processors is to head over to the egg and look up their mobile core 2 duos. That should give you enough info on speed/cache/fsb/generation/power consumption/etc. The problem is that they only have the higher end procs there. Link
BTW, do not get anything that is less than a 7xxx. The 7xxx is the high end of the old conroe/merom procs. If you want the latest and greatest, get a 8xxx or 9xxx They are the new penryn/wolfdale CPU's. The difference? 8xxx has only 3mb of cache, while the 9xxx has 6mb of cache.
There is also a letter code before them to describe the amount of power used. The T means that it is a standard power consumption model, or it uses 35 watts. P means that it's low power consumtion, using 25 watts. U is ultra low power consumtion. It takes just 5-10 watts. X is for the extreme edition. the old merom extreme procs used 44 watts, and the new penryn ones use 35 just like the T series. Q is for the upcoming mobile quad cores. They will use 45 watts.