Welcome to MobileRead, ColdSun!
The reason that e-ink isn't back-lit is basically that it's opaque. You can't pass light through it at
all.
That being said, I'd suggest that you arrange to have a look at an e-ink screen for yourself. It really does have to be seen to really be understood.
You may also want to take a look at the various reading lights that folks have come up with for reading from an e-ink display in the dark. There are several, and they work fairly well, and a don't necessarily give off more light than a back-lit screen would.
Of course, if that doesn't work for you, and if the back-light is a deal breaker for you, then I'm glad you found out about it
ahead of time -- far better that, than learning about it after you bought one.
I don't think that any of the forthcoming e-ink will support backlighting, but there are a number of other bi-stable displays in the works that may support it, and I figure it's only a matter of time before someone works out a lightwedge type of light for these devices.
Of course, you may be waiting a while.
