X58 boards were listed on Geizhals this morning.
The top of the range Eclipse board ends up priced just over €300. We like high-end hardware, and the board looks impressive, but €300 is still €300. The Platinum at €225 looks like a budget board in comparison, although it's still no bargain.
So, apart from new DDR3 memory and a pricey CPU, you'll have to cough up quite a bit for a new board, as well. The transition to Nehalem will be a costly one indeed, at least for early birds.
You can find the listings here
MSI has three X58 boards
More X58 boards get pictured
MSI's Eclipse X58 board gets pixelized
MSI X58 plans pictured