The Logitech Flight System G940 and the Saitek X65 are both dual throttled sticks.
Keep in mind that the G940 is a force-feedback stick (I haven't used one yet myself, but people either hate it or swear by it... there's not much in-between).
The X65 is a new kind of stick that does not move.. instead it measures how much force you're pushing (or pulling) on it. Again, I haven't used anything like that yet, but it seems like it would be pretty neat... no moving parts to fail (at least on the stick's Axis... what is the plural form of "Axis" anyhow?)...
Just keep in mind that both sticks are substantially different from the X52. I'm hoping Saitek comes out with something that does move, but a newer version of the X52... perhaps an X62 or the like... and of course, at a cheaper price