Get a beefy power supply, the one thing computers seem to never do is require less power as they advance.
While we would all agree get a beefy power supply. I would disagree on computers needing more power. Quite the opposite. The average person has changed their PC to need more power than it ever did. Multiple GPU's, a ton of drives, cooling you name it it consumes a ton of power. But once you have a system like that the next upgrade of comparable equipment will end up using less power.
When it comes to next gen CPU's they actually are going doing in power consumption each generation for a given category. High performance offerings WILL surface consuming great deals of power but these are usually insane items not inline with something from the previous generation.
Hate to use Toms but alot of the other charts are out of date:
Notice the i7-2600K/2700K use less power than their counterparts such as the socket 1156 i7-870. Now thats just a comparison between 2 consumer oriented models. The i7-2700K's performance greatly exceeds even the server to consumer oriented 1366 platform offerings like the i7-960 which consumer glorious amounts of power. Going yet another generation newer not seen in this chart the 3770K is rated for 77 watts TDP while the 2700K is rated for 95 TDP. In theory they both consume less than that and can consume more but the next generation continues to sip less power.
Graphics cards on the other hand are an interesting animal. Often times a model category is aimed to stay under a certain amount of power and not necessarily use much less than the generation before. But the continuing drop in process size and efficiency gained in new architectures tend to naturally still do this.
It would seem early tests indicate the GTX 780 is set to consume about the same amount of power as the GTX 580. Most of the cards in this particular chart either consume less power or about the same as their equivalent from a generation or two ago.
There is little wrong with going with more power than needed. The PSU will last longer, the efficiency is often at its best half way in and you will have room to expand. But unless your using more GPU's and more storage devices every year, computers tend to use less power as they advance.
