Sad, isn't it ? As a company grows larger, they grow more cautious, especially if they think there might be legal ramifications down the line.
That being said... I was looking for the specs for the Bridgstones on my car at Tire Rack a day or two ago - I believe it was listed at 14lbs /tire, if I'm not mistaken. You'd have to deflate the tire, but by standing on a scale with the tire / wheel, recording that weight, then weighing just yourself, and then finally subtracting 14 lbs (or whatever) from that amount, you'd know what the wheel weighs. A pain, admittedly - but it's better than having the tire removed from the wheel, then remounting / rebalancing it.
I have a feeling it's going to be fairly lightweight. Probably < 15lbs, as I believe the EX rims weigh that much, so these pie plates better weigh less than that. They're cast aluminum (alloy ?), so they're going to have *some* weight.
Incidentally, my issue with them isn't so much the looks (I'll deal with that, for tangible FE improvement) - it's the tight space between the valve stem and the wheel. Very hard to get a chuck on the stem.
Another option for checking, if you're registered with OwnerLink, would be to try the 'eStore' . Unfortunately, the last two times I've tried to access the 'parts' section of 'eStore', I've gotten an errormsg - this is with two diferent computers / browsers. So I wouldn't hold my breath, but I'd check that out - maybe it will work for you.