I have mixed feelings about Latin. I loved it at school and did A level. It was useful in my very traditional MFL degree because I studied Old Early French and a bit of historical linguistics. There's no doubt it can help with grammar (but I was a grammar fiend all along, so I doubt I would have had any trouble without it).
But... I have a bit of an issue with the idea of teaching Latin in order to help kids with grammar or to give them a linguistic base. It seems ludicrous to me that it would be necessary to teach a whole other language, taking up a whole extra subject's space on the timetable, particularly a dead one which will be of no long-term use to the vast majority of people, just in order to gain a better understanding of English and/or the modern foreign language they are learning.
Latin isn't magic! The problem is that grammar has for so long been neglected in teaching English and MFL . If you are allowed to properly spend the necessary time on that, then you really won't need to teach Latin.
I guess that when the fashion swung towards communication and expressing yourself in MFL and creativity in English, the only subject where it was still educationally acceptable to spend ages on grammar was Latin, because you don't have to devote any time to speaking it!
Don't get me wrong - it would be very sad if teaching Latin were to die out altogether, but I think the skills it teaches would be just as easy to teach through the medium of a modern language, were we allowed to actually do so (I'm an MFL teacher, incidentally
).