Not only can you find out info about WiiWare, you can view stats on all Nintendo games, including Virtual Console.
For those who have opted into the service (most likely a large minority) you can now view all the data which Nintendo has collated about a game. For example: LostWinds has been played 48,689 times at 3.4 hours per person. From this you can try and figure out how many units of the game might have actually been sold for the first time.
In addition to this you can see if a game is considered to be good for anyone or “gamers”, or people think it is casual or hardcore, or best played alone or with friends. With this information at your fingertips the possibilities are endless!
If you happen to have a Japanese Wii you can even view the registered sales:
Dr. Mario WiiWare: Duration 14:09, over 9.24 sessions (13,931 registered sales)
FF:CC My Life As A King: Duration 21:14, over 8.89 sessions (33,810 registered sales)
Everyone's Pokémon Farm: Duration 8:03, over 17.98 sessions (44,779 registered sales)
Obviously this data is flawed in the sense it only represents figures of people who have downloaded the Nintendo channel and opted in for data sharing, but nevertheless this makes interesting reading if you want to judge how popular a game actually is.
This feature doesn’t seem to be available in Europe/Australia at the time of writing, but it should only be a matter of time.
Thankfully someone is already compiling the VC & WiiWare game sales in a nice ordered spreadsheet so we don't have to. Feel free to email them and add your own findings.
Feel free to debate the findings below as always.