I did see some of the silvers taking seats, so it's not that EAU disappears. All it takes is patience and strategy. I had 3/4 EAUs in EWR-IAH legs and LAX-IAH legs. I'd admit that the re-booked Y fare helps to push me all the way up. However, all the EWR-IAH flights are quite full already, with the exception of CO811 still having 10 seats left. I think I would miss the EAU with lowly L fare, but that's already the best odds you could get.

April 1, 2011
CO303 - 1 F left
CO411 - 3 F left
CO61 - all gone
CO811 - 10 F left -- bare in mind that's 772ER, so guess how many PLTs are in there.
CO107 - 5 F left.

So it's not like the end of the world for PLTs, even for silvers.

EAUs are so much easier if you go back and forth S. Florida and EWR/IAH.