I've been too busy to do much cacing lately and didn't notice Topozone's demise (as far as I'm concerned) until I tried to pull up some maps last week in New Orleans to do some caching. I ended up caching with just my GPSr and cache description (horrors!) . Now today I'm headed out again and trying to figure out how to get a decent map.
Seriously, I much prefer to cache via map, and I hope that mytopo.com's option is made a little more useful and is linked from geocaching.com. I'm a huge fan of mytopo already - I buy their huge (36X48) printed maps on waterproof paper for areas where I cache/explore frequently. So hopefully they'll make their online topo map viewing more useful, like adding an X marking the spot of the search, and allowing various scale and printing options. I'm not likely to ever pay for a online topo map viewing and printing (in small format) service, but I am likely to continue to buy printed maps. So if mytopo.com can provide both services, I'd be very happy.