They've already snuck in a hardware upgrade. Isn't anyone aware that the DSi cpu is clocked 2x that of the original DS and has more RAM and a better screen?
There just isn't a portable gaming system out there that can threaten the position of the DS enough to force Nintendo to launch a successor. I can't even conceive a portable system that can. I'm sure Nintendo has the 2 screen system patented well that competitors won't find loopholes. Whomever, will come up with the next step in portable gaming, and I'm not talking about better graphics, if it's not Nintendo would definitely force Nintendo's hand.







