If G-Gundam was any indicator, I'd say a Gundam X would turn up to coincide when the series is eventually released stateside.
Same thing with the Turn A, though I really dislike it's design.
A Double-X would rock though. Especially if it comes with LED's to make the chest and fins light up.
Those MG kits from G were released to promote the DVD release of G Gundam in Japan, just like how Bandai released MG Patlabor, MG/HG Dunbines, and HG L-Gaims to get cross-promotional synergy with the DVD releases of their respective shows. Since Seed didn't take long to come out on DVD in Japan, Bandai put Seed MGs on the fast track.
Turn-A came out on DVD between 1999 and 2000 so we can forget about MGs of anything from Turn-A until Bandai decides to reissue it in some form. V Gundam is the latest non-Seed Gundam DVD release in Japan and Bandai didn't even bother with any MGs from V, so things don't look good for X as far as MG releases go.