it's better to take the cable car rather than London eye indeed!

http://www.dailymail.co.uk/news/article-2165872/London-2012-Olympics-crossing-Boris-Johnson-tries-new-50m-River-Thames-cable-car.html

The cable car has opeded for olympic which is crossed over the Thames!
And the cost is far too cheap for single, just ￡3.20 like tube fare, actually the oyster card is available...
I haven't taken London eye because of the high cost tho, I really wanna visit there and look over the East London view! It should be brilliant.