John,
It sounds like you already have the short-term solution in hand, with local file logging, which I'll admit is suboptimal. From your description, it sounds like you already know the CLI commands to make that happen.
Another idea is to set up a syslog server. I understand from your post that the customer "doesn't have a syslog server", but frankly, they're quite easy to set up, and there are many free syslog solutions to be found. The commands to do local file logging and remote syslog logging are very similar. Once you have the logs on the syslog server, local analysis is fairly straightforward.
What it really seems you're asking, however, is if/when you will be able to view IDP event logs (such as signature matches) directly from the J-Web. I've checked in with our Product Line Manager for a response to that, and will post an updated message when I get the answer to your Road Map question.
-Dave