Which software packages are you talking about, specifically? I seldom encounter libraries or packages that entirely do not support IPv6 (except for MySQL). At the very most it's a configuration flag or compile option to switch it on, if it's not on by default. I'm also curious as to how easy you'll find these homes with a myriad of routers either ISP supplied or third party, and the case you have to convince them that the little box they had needs to be upgraded with firmware or replaced entirely.

The other thing to note is that IPv4 won't just be left in the dust, it'll have to be transitioned - the immediate future at least won't be entirely IPv6, and the world will have a bit of time where dual stack is inevitable for parts.

If cable-companies can figure-out how to transition users from their analog cable boxes to the digital ones, I'm sure ISPs can figure out how to transition their customers to IPv6-capable routers. It should be dead-simple for the ISP-leased routers, but for people with their own routers, it's still an ISP-level issue. They just need to tell their new customers that they need an IPv6 capable router, and to figure out a way to transition existing customers that own their routers.

My cable company lost my business when they last year began requiring a "box" to receive TV. I already had a newer digital-capable TV, and did not want yet another gadget and tangle of wires on my TV stand. It was the final straw, the other two being the cost and the low-value content.

I actually didn't drop them completely, but did fall back to "basic" (no box required) + internet (cheaper than internet alone, which is what I really wanted).