I've said it before and I'll say it again: this is only a problem in the post-encounter-strutured editions of D&D (3e and 4e). D&D needs to return to a focus on exploration and adventure, not on the combat encounter. Every class needs to bring something special to the game. When your game is based around the combat encounter, every class needs to have something special to do in combat. When your game is based around exploration, every class needs to be able to do something in the adventure.The 4E power system is not the only way to provide interesting options for martial types. Vancian wizards are bad enough; I'm not playing another game with Vancian fighters.
As the adventure is much broader in scope than the combat encounter, this opens up a lot of opportunities for diversity that don't involve powers. For instance, if the fighter were the only class that was really good at combat and the rogue was the only class that was good at thief-related exploits (stealing, sneaking, snooping, spying, and so forth), you'd see a lot more opportunities for everyone to shine in an adventure. You wouldn't need to have AEDUs for non-casters because they could contribute in a lot of ways that were more meaningful than 2[W] + Strength damage.
That being said, I am not opposed to non-casters have powers. Not in the least. I just don't like that they use the same mechanics as spellcasters. I'd much prefer they were given encounter powers and at-wills while the spellcasters had daily spells. Naturally, some people will complain that it's impossible to balance the game when classes are on different power schedules. That doesn't matter to me. As long as the game avoids the 3e "casters do everything better" syndrome, I'm fine with it.