Yes, you should definitely go for it. All these government subsidies are due for a shake up at the end of the year - ie they might stay or they might not. Go for it now, whilst you still definitely can!
There is however one big barrier to insulation, which is the need to clear the loft of belongings, and then finding somewhere to put your stuff afterwards. It's a major reason why lots of people don't insulate their lofts.
However, there is a brand new invention, from a company supported by the Carbon Trust, which I’ve seen that solves this – a raised loft flooring system called StoreFloor. See
www.loftzone.co.uk for details.
It isn't subsidised by the Government but it allows you to keep your storage space. [:)]