Will all decent GPUs in the future need 2 6-pin power?

So I have been researching my build for a while now and I thought I was finished choosing components, until today.

The 8800GTX needs two 6-pin connections from the PSU, thus leading to a PSU with 4 6-pin connections for a SLI set up. I was planning a getting a 8800GTS and eventually going to SLI with that. So for the time being I will only need 2 6-pin connections on my PSU anyway.

My question is what about the 9XXX gen cards? Do you think that the high end 9XXX cards are all going to need 2 connections each? Maybe the chips will be super efficient and will not need it? Will PCIe 2.0 supply more power through the mobo? Will I want a new PSU in a year and a half anyway?

I was planning on getting the OCZ GameXStream 700W for $125 after rebate, but now I am looking at the SILVERSTONE ST75F 750W for $160.

Your opinion please.

Correct me if I'm wrong, but the connectors really don't matter, except perhaps for cable neatness, and a slight increase in resistance. You just get the appropriate adaptor. For instance:

http://www.newegg.com/Product/Prod [...] 6812887001

Couldn't you just get two of these and go from the Molex? (Not that this is very likely on PSUs that have the required wattage and ampage, because they will probably have the right adaptors anyway) Why does the actual connector matter?

I don't see why they don't just use thicker cables and use copper instead of tin plated steel..
Soon we'll have a 24 pin connector to the GPUs at this rate

The reason is simple. Copper is a soft metal. After a couple of times of plugging and unplugging the connector the connection would not be very tight. This leads to more resistance in the connection, arking in the connection that can cause spikes in the power flow and corrosion. All of which lead up to rapid PSU failyer. You need the steel to help maintain a tight connection. The tin is added to prevent curosion and to help the transfer of electrons. There are several PSUs that use gold plating.
Add to that the fact that while pure copper is an excellent conductor, oxidized copper is terrible. So even if the pins were copper core, they would still need to be plated with something to prevent oxidation. Also, many of the metals that work well for plating copper (nickel and cadmium among others) are on the EPA's "discouraged" list because of some of the biproducts of mining and refining them.
Steel is a crappy conductor though. I would think that most of the current goes through the tin and the steel is mainly for mechanical strength. Like high voltage power lines are frequently steel core with aluminum around it. Steel's poor conductivity is what helps make transformers possible, the core losses would be very high if the core material (steel or other iron derivatives usually) were a good conductor due to eddy currents.