To be honest, I can't see rates rising anytime soon, irrespective of the changes to the allowances. A lot of people have already built up their ISA's, so the effect of the increase will be small, compared to what's already out there.
Also, the base rate has remained the same since March 2009, yet over the past 5 years, rates offered to savers have plummeted.
I remember a few years ago, I had the chance to fix at 3.5% for 2 years - I opted to fix for 1 year, as I thought rates couldn't go any lower. How wrong I was, 'cos the following year, the best I could get was 3%. Again I chose to fix for only 1 year and I got lucky, 'cos the following year, I managed to get a 3 year fix at 3%. That was last year and I can't add to that ISA and the best I found so far is a 2 year fix at 2.75%.
I'd like to say that they can't go any lower, but I've said that a few times before and been wrong :(