The X1 looks to be launched either just after the new-gen X3 is launched or just before (like the X3 and old/new X5 timing).
Therefore, the x3 will gain about 10 cms upon redesign in in 2010 and it will have about the same length as the first gen X5 at 466 cms. The X1 will therefore in fact be just shy of the current X3 in size (within 5 cms): that is my guess.
2012 335i, saphire black, coral red leather interior, sport line, sport suspension, 6mt, premium package
2011 Lincoln MKX, black on black, premium package - that's right! Techno-Groovy baby