That is a great option for people who have a dd-wrt/tomato/etc. compatible wireless device.
The goal of the post was for folks who don't already have a solution setup and to get people familiar with EC2 now that it has a Free Tier and see some of the "not so obvious" things we can do with.
You don't need to have dd-wrt. I've got a used corporate firewall (which also works as a router) it has built in VPN and built in support for updating to DynDNS... I bought it for 80 dollars, not too far off from vanilla routers - I did have to pair it with an access point, so costs aren't completely comparable.
I'm sure comcast would not like it, and the dynamic ip issue.