Also, it makes the publishers seem doubly hypocritical, in that it flies in the face of all their anti-piracy arguments. Nothing promotes piracy as effectively as regional restrictions and regional pricing.

Why do you think publishers would be willing to allow those services to sell their games if the services won't agree to their price point? Do you honestly believe that those services wouldn't jump at the chance of using the higher price (bigger profits after all) if it really were set by the publisher?
Services may *claim* that they want to sell affected titles worldwide, but so far only two have actually proven to some extent that they almost mean it. The first being Steam in the case of Ubisoft titles and EA titles -- outside of Japan.
And the second being GamersGate who don't actually enforce their regional restrictions as strictly as you'd think (try buying EA titles from GamersGate UK for example -- it's possible pretty much regardless of where you live).
Valve won't do a thing. Regional restrictions are imposed at point of purchase only. You can gift to any country and the person being gifted will be able to play the game -- I have plenty of games that have been gifted to me from a friend in the US.

The services do agree to the price point, the US price point, but not to any finagling of that price point just to extort other markets. Perhaps their size and vulnerability play a part in choosing not to. Price gouging tends to upset people, and if you're a smallish operator in a market that relies almost exclusively on word of mouth advertising and with little to nothing to distinguish your product from a competitors, you might decide to avoid that mess and just stick to one region, one pricing policy, and offer international customers only those titles you can at the same price point.
But they can, and have already shown great flexibility and willingness to fuck some customers in the ass at the behest of publishers. If it became commonplace practice for legions of US customers to do this, thus negating any point to the region pricing whatsoever, do you think the publishers wouldn't put pressure on Valve to start waving sticks?

If it became commonplace practice for legions of US customers to do this, thus negating any point to the region pricing whatsoever, do you think the publishers wouldn't put pressure on Valve to start waving sticks?
it already is commonplace among people who have trustworthy friends in regions where games are cheaper. As long as stolen credit cards aren't used and as long as Valve could in no way prove that gifts were being sold, there is nothing they will do to stop cross-region gifting.

Sexist bastard/bitch (circle where appropriate)! Kill the daughters too! Equal opportunity pointless killing

Weirdly, that's the point of Left 4 Dead...

But not of left 4 dead 2 because you can kill black zombies as well which is wrong

Ah, of course. The wonders of political correctness.
Speaking of L4D2, the intro cinematic was released (leaked?) and it's freaking awesome.

It's not leaked. The final 'coming soon' screen shows this was intentional.
It does look good. But I'm going to need to see two things before I consider buying it: major price reduction and a lot of support for it.

Oh it was leaked, as in leaked in the same way as certain TF2 "Meet the..." intros were leaked.