Steadfast, PV modules consist of 5 layers: The glass (which in your case is broken), a layer of EVA (think "sticky clear plastic"), the solar cells and their connections, another layer of EVA, and a back panel made of tedlar (to give it impact resistance from that side). When this sandwich is put together, it's put in an oven, where the EVA is melted, glueing the cells, glass, and tedlar together (think "hamburger with cheese on both sides").
The glass is what gives it rigidity, and that's what you've lost since it's broken. Unlike comments in this thread, water is not a problem by itself, for a broken panel, the EVA still seals the cells and connections from both sides. If that water grows stuff it may impede the light going through, which of course will affect the output of the panel, but other than that it's not an issue.
Most of the time I've seen broken panels work fine, at least for a while. However, lacking rigidity the wind will do 'm in when left outside. The flexing of cells and soldered connections will eventually crack/break them, and that's the end of the panel. Not sure how sealing will help; it won't make the panel wind-resistant again. Adding a layer of plexiglass or polycarbonate might help, but you'll likely loose quite a bit of output.
To test if your panel still works, put it out in full sun and measure the voltage. That's "Voc" (for 'open-circuit') of the panel. Now flip the panel over so the cells are in the dark, connect your multi-meter in series with the wires, short-circuiting it, flip it back into the sun and measure the current. That's "Isc". Compare with the spec sheet (if it's a hot day you'd have to correct for temperature as well, at least for Voc, which goes down .37% for (roughly) every 2F above 77F. If both values are still in the ballpark, your panel will still work.
Thought I'd give you a quick explanation, so you can better judge what may or may not work (and so you know what you're up against). Good luck!
-RoB-
