One thing I don't understand is:
How close are the rental costs going to be to the value of the bitcoins mined? If it's over 50%, it's hardly worth it due to the risk involved. If it's under a certain rate, then it would probably be more profitable for you to mine the bitcoins yourself.
And being as bitcoin mining doesn't use a lot of network bandwidth and everything minus the video cards (and motherboards in some cases) can be the lower end stuff, I don't see how it could realistically be more expensive than renting a lower end dedicated server.
Would rental reflect the price of the bitcoins mined? Or would they be fixed?
It's absolutely going to be as affordable as possible: as you suggest there's no point using the service unless the miners themselves are making profit! It's something that's impossible to elaborate on honestly, but the way we see it is the charge will be based on rent, electricity and systems administration costs. We're totally not going to be selling "lemon" contracts that lose more money than they make: that would be pointless.
We're not looking at fixing the rental price on the bitcoins mined at this time (might as well just sell the coins if going down that route perhaps). We're seeing this as more of a hardware venture: you'd be able to gain access to a bitcoin miner, but theoretically our business model would allow those cards to do anything, so if someone comes along with some OpenCL based High Performance Computing project we'd be able to slightly tweak our offerings and diversify.
We see this as a great opportunity both for serving our "bulk" customers who wish to start larger mining operations, and our overseas customers where it may not be practical to ship a physical miner halfway around the world.
Since the offer says your service performs all the support and maintains the systems, does that mean the customer doesn't determine the choice of miner, which pool is used, etc?
Hopefully we would support bespoke systems, we'd just need people to give us the correct access rights. Pool choice is of course up to the consumer: last thing we want is to centralise on some pool and force people to us it: I'm actually loving the free market competition right now and it's better for the health of the network. These are all very good questions, and points have been raised that are going to be very helpful to us if it turns out we can provide this service.