I agree with the OP 100% Hilton no longer seems to make any special effort for Diamonds. As a result I made Plat with *wood and *wood Plat rocks. I have consistently received suite upgrades which matters far more to me than a free breakfast at Hilton (which 50% of the time or more you do not get because "you have already been upgraded").
The fact that I am now Diamond through 2008 simply means I can plan orderly redemptions with Hilton and resonably expect to get the hotels I want to stay in. Well done HH you have lost a high spending customer.