So, after Schockwellenreiter wrote about it, now the overview page is here too. And wonder of wonders, it's the same one as for the ping. So much functionality, and everything with just one address!
And his suspicion that Python is involved is correct too. The XML-RPC server is written in PHP (almost the original one from Reinvented Technologies, just ported to PostgreSQL), but the cronjob (the part that runs every 5 minutes) is written in Python.
The overview page is especially helpful when first trying it out - you can see when the ping goes through and whether it goes through. Oh yes, you should only ping either weblogs.com or simon, otherwise you get strange error messages back from weblogs.com.
Of course everything is still beta at the moment, so if you try it and find problems, please send me a message and I'll take a look at it.