Take a close look at XYMon, previously called Hobbit. Easy to use, ton's of plugins (big brother compatible).... Really nice over all, easy to understand web-based interface, alerting, graphing, etc...

The really big worry if this goes through is what happens on the hardware side? Newer Sun hardware is really pretty amazing, and with the upcoming Rock processor it's only going to get better. If IBM buys Sun, we might lose an entire architecture, and that would be a shame.