Nigel, you're looking for a piano degree, or a composition one? I don't think it really matters if you're on "ok" or "very good" or "poor" pianist if you're after composition. Sure it helps, everything does.
In composition usually they require a few scores (2-4 usually) of different styles to prove that you actually know music and that you can actually write.
Film music is no different than any music. If you go to a classical music department, more than a filmy one, you'll end up with too much contemporary music. I find that this is good, because it opens your mind and ears. Study 3 years taking in all the bullshit, even if you don't like it and then do whatever you want. Film music does not exactly take huge amount of music, it just takes knowledge of writting as everyone else (<-ouch this sounds bad!)
What I mean is that you don't need special studies to do film music, you need to be able to compose and practice in visuals (like the CGEmpire competitions can be great practice, as well as getting trailers, animations, etc and underscoring them). I don't think that you can learn too much studying for film music. Sure there are degrees, etc, but I personally don't see the reason.
Since you are after studying "seriously" (whatever this may mean), a couple of thoughts:
* Avoid like the plague those music-tech-schools which offer a degree or diploma of some sort in 6 months. It's crap! Plain and simple. You won't get connections through there, no matter what they say, and you won't learn anything in 6 months that you wouldn't be able to learn on your own! MIDI? Samples? Come on! Ask me, ask Marius, go to cgempire and make tons of thread asking questions.
* In the end you will be getting a degree! This IS something great! Think ahead. you want to be a media composer, but how many people in YC do you know who are doing this effectively? 5? 10? No more! Composers living off composition? 0? 1? 2? A degree means that you went through a lot of trouble getting it. It means that you have a "certain amount of knowledge". It means probably that you can TEACH! It means that you can get a Masters afterwards. How many in YC have a BMus or going for a BMus? A few. How many have an MMus? Very few. A PhD? None (is there anyone?) More degrees mean that you can simply be "ahead" somehow. Even if it means 0.5% in the media business, since noone will care if you have a degree from LSE or something.
Still I've found out that starting with "I'm blah blah and I have a PhD in composition" does force people to read and listen a bit. You get by the very first hurdle!
So what can you do with a BMus? Can you teach? Can you go further? Research on your options!
* Funding. Scholarship! I have a 3 1/2 year scholarhips. It covers tuition fees and a monthly stripend. If you want details I'll simply say that I'm covered for 3 years tuition fees ($18,000), plus $1,200 per month for 42 months! I am (still) being paid to study. Can you accomplish this? It's great! It's like working pretty much!
I got my scholarship from Greece, from the National Scholarship Foundation. Is there a simmilar place in your country? In the UK? In the USA? Can you get work once in the foreign? Can you work? Will you have time? Will you make it or have a nervous break down?
* BMus can be anything you want it to be really. You take modules so you can pick ethnic music for all they care, or performance, or composition, or musicology. Anything! It's up to you to build your course. Not completely but you do have some element of control.
That's all for now