LCD TV Becomes Bulletin Board good or bad idea?

Wow, the prior answer is very accurate, but I think that in this case most none of that worry is needed.

The design sounds very simple and will not take up much of the FPGA resources.

Go for it, should be rather simple to build, and should take almost no power.

There are a few kits already out there with all the hardware you need in place already.

You could probably run it for 10 years with no heat issues.