There are professional companies out there that will reglaze tiles. (And you can buy yourself a Learn-It-Yourself book and video kit if you want to get into the business.) Anyways, the problem I have is I haven't heard if these pros clean out the grout first. The reason I bring this up is because if they don't clean it out, then the reglazing process puts the new glaze ON TOP of the old grout! I don't suspect it will 'stick', plus, the grout will be the same color as the tiles. As you're aware, the grout is usually white, almond, or some 'matching color'. I've never seen it the same color as the tiles.
With this in mind, if you contact a pro to reglaze, talk about grouting. I would GUESS that the 'perfect job' would have the grout removed BEFORE the reglazing.
My best to ya and hope this helps.
Jay J -Moderator
PS: Yea, I wouldn't do it as Steve: says either. The tiles will look like painted tiles. (Not exactly what you want ...)