Yes there has been devaluation. However, no more than with other air and hotel programs.
I'm not leaving HHonors. With the current 50% bonus instead of miles, diamond bonus, and 3 points per dollar at Hiltons on HHonors Visa, I am getting 23 points per dollar spent. If you value at a penny a point, that is 23% return on laundering of my company's money (since most paid travel is business travel). Even at a half cent per point that is still 11.5%.
Anyone who uses HHonors points for non-hilton rewards is already throwing away a large percent of their value. Using points for air travel has always been unwise, just more so now.
I will requalify for Diamond by early May. If someone can find a good reason for me to start participating in a second program, I am all ears.
marc