I've also toyed with this idea, but I know more than one fellow fish nerd who has done so and regretted the permanence of it. Either you use a little silicone on the corners and have it easier to remove if you want, downside is gunk getting trapped back there, or you seal the hell out of it and never ever get it off.
4/26/2012, lost the finest man. Rest easy Pops...
<--Great Danes are people too!
180g, Fluval FX5, 404, 128watts t-8, low tech, heavily planted, with Albino and reg bristlenose plecs, Congo tetras, Amanos, a herd of Corydoras Sterbai, Boesmanis, a big old common plec, & Otos. 32g tall eclipse3, fluval403, with a handful of bristlenose plecs.180gallon corner in-wall build journal