After a wander round the blogs, business forums and newspapers, the general consensus seems to be scepticism on the beneficial effects of cutting VAT to 15%. Apart from the risk of many retailers not passing it on (or was that the real agenda - typical Gordon move - pretend to do one thing whilst really doing something else - journo's are so easy to fool - basic rate tax cut/abolition of 10p band - I rest my case), it will cause havoc with many websites which are less easy to amend than traditional accounting systems - never mind the complexity for those (and there are many) who still keep manual books and are on cash accounting (I won't go into detail but believe me they won't enjoy Christmas).
If he really intended to help those small businesses at the bottom of the chain he should have hiked the VAT threshold on turnover at which a business must start charging VAT to customers to at least 100k. Small businesses need a fair chance to get going before being hit by the complexities of VAT.
Some interesting points on this issue on Mark Wadworth's blog.