So even though I don't know if my first choice of business name will be selected (I'm 99% sure, but who knows what could happen?), I went ahead and grabbed the domain name for it anyway. Worst case I'm out 10 bucks. I figured it was safer to grab it now, rather than wait until the LLC paperwork is all official only to find out that someone else snagged the domain name. The domain name I would want for my alternate LLC name is already taken, so I would have to come up with something else anyway in that event.
Granted I'm probably months away from actually needing a domain name, but I figure it's better to be early than to be too late.