Recently someone posted an interesting TED presentation in the General forum.
In it, the speaker talked about pasta sauce. He described how companies would conduct surveys to discover what it was people wanted. A man whose job it was to analyse this data set about determining people's preferences in a new and different way to the established methods.
What he discovered was that people don't know what they want. They think they know, but they don't. From his surveys, he discovered that when presented with a lot of various options, people invariably had different tastes. People would tell you that they wanted thin and watery pasta sauce, but what they really wanted was thick and chunky.
Almost overnight, thick and chunky pasta sauce became a major market.
So now we have dozens of different varieties of pasta sauces. One to suit every taste.
This brings me to 4e. It is another flavour and one that you may not realise you wanted until you give it a good try. If you'd asked me a year and a half ago what I wanted out of a system, I would not have given any response remotely like what 4e is. And yet, it is now by far my favourite system of all time.
It has it's flaws, but for the most part, it's now what I prefer. So I'd recommend buying the PHB and DMG (they're pretty cheap all things considered), getting a DDI account for three months, and running or playing in a game. If after that time you find it's not the system for you, then you can always sell the books and look for another flavour of pasta sauce.