Log analysis is the heart of the product, but we also gather system metrics, provide notifications (scalyr.com/helpalerts), and we recently rolled out a basic active-checks feature (scalyr.com/helpMonitors). There's lots more to be done; for instance, we don't have any SNMP support today. But the vision is to be a full-spectrum tool, and we're actively working toward that.

As for the licensing model: we're going to move to per-GB pricing anyway, so no worries there. If you'd like something more concrete today, e-mail us at contact@scalyr.com and I'm sure we can sort out any pricing concerns.