The LF-A could be done for GT2, but it wouldn't make a whole lot of sense.
Besides Nissan, I think the only others that really jump out are a Mazda RX8 built by Speedsource (I doubt this one), and maybe Champion with an R8 GT2. (GT3 to GT2 conversion is possible, but it's not exactly wise)
Yeah, it was announced at Sebring, pushed back to Houston, pushed back again, and then never heard of again.