JMG - OUTSIDE NOW!!! Any more of those pasty/tin/fudge comments and you're for it!!!
Dreams - I moved down about 6 years ago and live in Falmouth. Its a gorgeous place to live but has some huge downsides. The property prices have shot up and keep going up, will probably start to level in about 2 years but atm they're still increasing by about 10% a year, 20% in some parts. Don't know what you'd be looking for but an average 3-bed semi in Falmouth or Truro is about 200-250k and in the less popular areas that drops to about 180k. DON'T even consider moving to Camborne or Portreath, though Redruth is not too bad. Camborne has the worst crime rate for down here and is usually where all the murders occur - nice!!!
There isn't much work down here and its all fairly low paid. There's a lot of industrial/IT based work around Redruth area, Falmouth and Truro is mainly care work and admin/secretarial/managerial type stuff. There's a few big call centres down here if you want a job to tide you over but it's not career making stuff. The only other real option is tourist based work which is the main work available in the smaller areas and in places like Penzance, St Ives and Hayle.
The pace of life here is quite slow which is nice if you want to relax but if you want to get anything done you might have a hard job sometimes. Some facilities are limited as well, eg broadband. If you're in Falmouth or Truro its fine but if you move to the outlying areas it can be difficult to get 'new' stuff.
I've got to put my one pet grieve as well though. If you want to have a baby - DO NOT be in Cornwall when you do. The main hospital in Truro is c**p, to put it nicely. Its not too bad if you need an op or something but it is renowned for having extremely bad geriatric and natal care.
Anyway, sorry to sound so depressive about it!! It's mainly the day-to-day living aspects that are hard in Cornwall. The area is gorgeous though - Redruth is more industrialised and Truro is the only city so is naturally full of offices and shops. Falmouth has got gorgeous beaches, but getting the weather to enjoy them is difficult of course!! The childcare doesn't seem too bad down here (don't know if you've got kids or how old they are) but some of the schools are 'lacking' - you'd be best sending kids to school in Truro.
Hope this hasn't totally put you off - if you need anymore info just ask. And don't listen to a word jmg says - that's what a love of Chelsea does to your brain!!!