Great shot. I live in Arizona (not near Page, though) and could fairly easily drive up there on a two day trip. However, I have never been and likely never will for one reason. Everyone I know who has gone in the last decade says that it is always full of photographers with tripods no matter when you go and you have to fight for a place to get a shot. Just too popular and too small of a space.
Am I wrong about this?
I've been twice to Lower Canyon and thrice to the upper. Upper is indeed busier, especially in high season, but my most recent visits to both where Jan (2011) and Mar (2012) and you often had sections to yourself. Most people on the lower respect photographers and will happily wait the 20 secs of a long exposure! Time wise, you want the sun overhead to get best illumination to the bottom, but if you prefer more contrast then adjust accordingly.
Upper Canyon you have to do tours, Lower you can just drive up and park and do your own thing. The extended tour is certainly worth it. In March I went twice, and still never completed all of it. I also did the upper and the only down side is the guide makes the pace and suggests pictures. Lower is cheaper and although it does not have such wide openings as the lower, then does not quite have the same majesty as the upper does, but I find it more enjoyable.
Off season make sure you pack gloves etc - it really is quite cool down there, tripod of course and pack a wide angle and a mid-range zoom, spare battery...
For general info on other photographic opportunities, check out Laurent Martres Books...