"This year’s general election is likely to be the most open and unpredictable in a generation. So you have a right to know where we stand. I can promise voters wondering whether to put an “X” against the Liberal Democrats that there are no backroom deals or under-the-counter “understandings” with either of the other two parties."
You can see why Clegg is broadcasting this message. A politics which says "let's stand up and be counted" is red meat for Lib Dem activists.
But it will also be received with interest in Labour and Tory circles. The more uncertainty Clegg can create about his intentions (in the event of a hung parliament*), the more reason there is for the other leaders to woo him and his party. And, as Steve Richards suggests in today's Independent, it's that courtship, more than anything, which could give the Lib Dems a profile in the months ahead.
*N.B. I don't actually think there will be a hung parliament. But it's enough of a possiblity that people inside the Labour and Tory parties are taking the idea seriously. Labour types, in particular, feel (hope?) that they may come to rely on Clegg's support.