Well as I mentioned in the MTBR thread, I work for an insurance company.
Your homeowners policy should cover a bicycle without any problems. The issue on the MTBR thread was that the guys homeowners policy was being cancelled, and he correlated it to a recent claim for a stolen bike. Truth be told, it could have played a factor into why the company would want to no longer insure the homeowner policy. I don't see it happening myself, but the industry is getting a bit extra cautious as of late.
If you want to get insurance specifically for your bicycles, you'll want an Inland Marine floater. What that is is a policy for items that "float" around from one place to the next, and will be covered even if they are stolen from a premises not scheduled in the insurance. So if you have your bike at a friends house, it gets stolen, you're still covered. I don't believe the homeowners policy wouldn't react the same way, because in this scenario, it wasn't taken from your house/premises.
Now even if your bike is covered by homeowners, you need to check for how much. I'd be willing to bet there is a maximum limit per bicycle. So even if your $2,000 bike gets stolen, you may only be able to be compensated for $500. This is yet another reason to get an Inland Marine floater, you could schedule higher coverage limits for each bicycle.
The premium for the Inland Marine floater would be fairly small. A quick web search is telling me about $9 dollars in premium for every $100 dollars your bike is worth. This charge would surely vary by company, but lets just assume its correct. If you have a $500 dollar limit on your bike, you'd be charged $9 x ($500/$100) = $9 x $5 = $45 dollars per year.
$45 per year isn't too bad in my mind if you really value your bike and want to make sure you have adequate limits in place.