This is in the realm of you arguing for the sheer point of it.
Your going to use Socket 775 in you argument against compatible? Your going to win on that one.
The whole point in this doesnt really have anything to do with forward or backward compatible. Which it does have to a point, thats even another bonus!!
The point is each processor in a series AM2/AM2+ or AM3, from the lowest Sempron to the highest Athlon/Phenom will run on their matching socket.
All AM2 processors fit two sockets - (AM2/+) AM2 boards have DDR2 800/HT 1000/2000 and PCIe 1.0
All AM2+ processors fit two Sockets - (AM2/+) AM2+ boards have DDR2 1066/HT 2600/5200 and PCIe 2.0. Plus its a bonus if its a Quality AM2+ Board, All AM2/+/3 processors will run on it.
All AM3 processors fit three Sockets - (AM2/+/3) AM3 boards have DDR3 1333/HT 2600/5200 and PCIe 2.0. But alot AM2 boards were never gave a AM2+/3 processor bios update because of power issues.
AM2/+ processors are being fazed out, might even be hard to find one by the end of the year. Dropping 65nm.
The point in this is, if you have a AM2+ board and want to upgrade to a better AM3 processor now or later you can without buying a board and memory.
The second point is from the slowest Sempron to the fastest Athlon/Phenom will all fit their perspective socket.
There is not a different socket for the Sempron, a different socket for the Athlon and another one for the Phenom (This is what Intel is doing)
Your going to use Socket 775 in you argument against compatible? Your going to win on that one.

The whole point in this doesnt really have anything to do with forward or backward compatible. Which it does have to a point, thats even another bonus!!
The point is each processor in a series AM2/AM2+ or AM3, from the lowest Sempron to the highest Athlon/Phenom will run on their matching socket.
All AM2 processors fit two sockets - (AM2/+) AM2 boards have DDR2 800/HT 1000/2000 and PCIe 1.0
All AM2+ processors fit two Sockets - (AM2/+) AM2+ boards have DDR2 1066/HT 2600/5200 and PCIe 2.0. Plus its a bonus if its a Quality AM2+ Board, All AM2/+/3 processors will run on it.
All AM3 processors fit three Sockets - (AM2/+/3) AM3 boards have DDR3 1333/HT 2600/5200 and PCIe 2.0. But alot AM2 boards were never gave a AM2+/3 processor bios update because of power issues.
AM2/+ processors are being fazed out, might even be hard to find one by the end of the year. Dropping 65nm.
The point in this is, if you have a AM2+ board and want to upgrade to a better AM3 processor now or later you can without buying a board and memory.
The second point is from the slowest Sempron to the fastest Athlon/Phenom will all fit their perspective socket.
There is not a different socket for the Sempron, a different socket for the Athlon and another one for the Phenom (This is what Intel is doing)