However, when MDF gets wet, it deteriorates. so Make sure you get a couple of really good coats of paint on it before you let it get wet! Don't forget the underside as well.
Amen to that. I work for Sauder Woodworking (
http://www.sauder.com/ ) so I've seen what water can do to MDF (medium density fiberboard) and particleboard and it isn't pretty. I'd definitely seal it up with a good spar varnish or a RTV silicone paint. Anything to seal the water out. Over the long term, water will swell MDF and cause issues like swelling, telegraphing, etc. They do make a grade that is specifically for use in bathrooms and kitchens -- anyplace that sees a lot of humidity/water. It uses a phenolic resin instead of urea-formaldehyde to bind the wood fibers together. Phenolics are more water resistant than UF.
The stand is looking very nice -- now just seal it and you should be set.
Shane