It says the CPUs should be shipped in July or August but at least you can pre-order one and be one of the first to get one.
The cheapest Intel Core 2 DUO E6300 works at 1.86GHz and uses a 1066 FSB and comes in a retail pack for £158.57 incl. VAT.
Second in line is the Intel Core 2 DUO E6400 that that works at 2.13GHz with a FSB of 1066MHz. It costs £193.82 including VAT in retail.
All Conroe Core 2 DUO CPUs are using the LGA775 Conroe socket, the same as LGA 775 but you'd better check if your current board is Conroe compliant. Both these CPUs have 2MB of cache memory only.
To round off the offerings, the Intel Core 2 DUO E6600 works at 2.4GHz and has 1066 FSB but this chap has 4MB of cache memory. It is listed for £264.32 including VAT.
The Intel Core 2 DUO E6700 works at 2.67GHz and uses 1066MHZ FSB and comes in a retail box for £440.57 including VAT.
And the Uber Gamer Intel Core 2 DUO Extreme Edition X6800 works at 2.93GHz and has 4MB cache memory, uses LGA775 socket and a retail price of a saucy £810.69 including VAT.
Those CPUs are only compatible with new Intel 965 and 975X socket 775 motherboards and the older 975 boards won't work with these CPUs.
You can pre order to your heart's content here. µ