I agree that for most of people solar is financially good decision, provided you will still be living in the house in 4-5 years. The return-on-investment time for the initial investment will of course depend on individual circumstances. The technology will improve but considering the current installation cost and the raising power costs, it is worth jumping in now.
And Chris, you are absolutely right, there are lots of dodgy installers offering cheap deals and horrible/dangerous installation practices. Whirlpool forums is a great place for advice and finding reputable installers. They may cost a bit more but at least your panels won't fall off in a year
Regarding the batteries, the technology is still new and the prices will most likely go down in the next few years so it is probably worth waiting. But if you are getting a new solar installation, make sure your inverters are designed to worth with batteries, otherwise you may need to swap them in few years.
Glen, unfortunately the cost will go up even more as people go off the grid as there will be less people to pay for the grid infrastructure.
And if too many people go off the grid I would not be surprised if they try to introduce new fees/taxes to the off-the-grid people to subsidise the running costs of the grid.