Core i7 Worth it?

Ey guys i looking at building a computer im stuck however on what CPU to get and thus the m/b according to what i pick

A 920 here is $50 more expensive than the q9550 and i hear it kicks it arse (Is it true???) however im stuck with what to do for m/b

The core i7's do they really need overclocking?, i can get a m/b for ~400 which isnt the best for o/c or around 550 which is gud for o/c is it necessary to overclock? or will it be in the near future. (Also stupid question if i say get a the $550 Asus m/b can i use it until they change the cpu socket type or will i need to change it if i go and buy a new processor in a year or twos time??)

Im looking at a ati 4870x2 so im tyring to aviod any bottle necks any suggestion im happy to ponder over so suggest ahead

Thanks in advance Trent

Naw its more i hope to keep it for at least 3years + not just for games also for mi uni cad software, but am debating the preformance increase vs the cost since ddr3 is more pricy again my initial budget was 1500 and i can get a q9550, 4gig ram, m/b, 4870x2, but since i want it for the longer period i was thinking in 2 years time games would start to support multi threading thus the quad will be useful and was tossing up buying an core i7 if the boost warrented the gain. or buying the low core i7 range now and buying a faster processor in 3 years time since most of the cad work i do is mathematical modelling ram and processor are the main requirements

Cheers Trent

leaning towards it after read how to o/c a 920 to 4gHz stable lolz ouch ill need a new power supply for the processor + and 4870x2 prob a 1200W to be safe

http://www.bit-tech.net/hardware/2008/11/06/overclocking-intel-core-i7-920/1