My insanely awesome girlfriend got me that exact shirt for Christmas ... I wore it when I went to the midnight release.
I'm not sure if NECA has ever done a neon sign before ... but they may consider it. They knew they were on to something with the BioShock 2 license. But I think it is even bigger than they thought it would be. Usually when they do a video game figure, they only do 1 or 2 characters ... this has prompted several figures already (one of which sold out) and has a few more on the way. Plus they've already started making props. Who's to say that they wouldn't make a neon sign ...
I'd love the Plasmid sign ... and I'd probably get the New Years one too:
HAPPY NEW YEAR 1959 sign (in-game)
Just for reference, DC Direct makes neon signs all the time. They have full sized (Superman, Batman) and mini signs too. And they are making a nice one for True Blood:
MERLOTTES sign