that's pretty good.  Anyone else providing a similar service that accepts XPUBs and provides notifications?   For a robust solution, at least one fallback/failover is needed.

I must say, after going through most of the shopping cart interfaces linked to on the wiki, I'm rather disappointed.   It doesn't seem like there is really any activity or updates, so I guess most everyone is relying on third parties rather than running local instances.   :-(   that, or people are rolling their own private solutions with bitcoind, something I've done in the past.