Geoff Hubbard Returns for X-Men 3? tells us that X2: X-Men United supervising art director Geoff Hubbard may be back for the third installment:

His other credits include HARRY POTTER, SPEED, SWORDFISH, PEARL HARBOR, and NATIONAL TRESURE. Geoff (although not mentioned on IMDB) last worked on SUPERMAN RETURNS, also as an art director. The X3 art department is now located in Los Angeles, and is expected to grow considerably in the next few weeks-months. They are close to getting a new costume designer for the project. We have no idea who he or she is, but stay tuned to XMF for updates on that!

For Hubbard’s full filmography, click here.