squeaky explains the reasons here. No data has been lost.
I also recommend bookmarking IJ's twitter page - Squeaky is usually quick with the updates and giving us relevant information, i.e. what is wrong, what is he going to do to fix it, and how long will it probably take.
General question: as myself and various other people suffered from the typical journaling withdrawal, do you know if there's some sort of "refuge" community elsewhere, where users could post and exchange news during downtimes? I guess GJ is still too unstable, and I don't know much about other journal services, but on the other hand, I'm not sure if people were happy about using an LJ community for that sort of thing. But a central meeting point would be nice. Suggestions?
Eta: I'll set up a poll this Friday to outline the options you mentioned and see what people would prefer. Will link to it here.
Eta2: the poll.