That's a great sign, as far as I'm concerned. It means the tablet's in demand, meaning that once Asus can ramp up production these things should be flying off the shelves. THAT means that analysts and such should shut up about there really only being an iPad market, not a tablet market, and developers who've held back from making Honeycomb apps should jump back on the bandwagon.
It's a little bit of short-term pain (having to wait) for quite a bit of long-term gain (a more viable market). Whether they meant to or not, Asus has created some welcome hype around unmet demand. That's a good thing if your objective is a successful Android tablet market.