I would say that the "attach rate" isn't great, especially considering it's been on the market for two years now, but two things to consider:
A) Handheld's tend to have a lower software 'attach rate' than consoles and
B) Digital sales are picking up so much steam (and aren't tracked - or trackable, really, that I know of), that the software numbers are certainly misleading in that regard. Between the VC and 3DS eShop, I have no doubt that the 3DS is shifting decent volumes of software each week. Same likely can be applied to Vita.
Bah!







