Well for SM'ing, the bigger screen is a real win: I (but perhaps not others) really need to see two pages at a time when running a show and the current iPad lineup's screens are too small for that. Combine that sized screen with the stylus and iAnnotate (or the like) I can finally see moving away from printed scripts for relatively cheap money.
As for lighting: your line "it's just wireless" is pretty funny to someone who's debugged DMX perched 25' up on a ladder, alone, in the early hours of the morning. I'll grant you that the larger "pro" factor is not a must have for that use case but the elision of wireless computer control with a traditional fader board form factor is pretty exciting when it comes time to write cues (or run an unscripted show live).
Do you believe that USB --> DMX is somehow preferable to wifi --> DMX via Art-Net? Every place I've worked (including the venue I own) has either made this transition or would dearly like to make it. Granted, large installations probably have other concerns but for small spaces (figure 50 instruments, 300 cues, and one or two tech folks) Art-Net kind of rocks.