There are a couple of issues here and philosophies about which solution (do something vs. do nothing) and when it’s appropriate (no money, no time, etc.). I can’t speak to those nebulous scenarios, but if you’re designing fullscreen comps, leave the dogma behind and simply design at 1×, then scale up with “Image size” to 200% in Photoshop. No, 320×480 won’t look sexy to your co-workers, but assuming you’re using vectors and layer styles, it’ll save you from a ton of work *and* it will be pixel perfect.
Here’s an example of scaling up I did.
You can probably snap to even pixels in Photoshop to avoid blur going down to 1×, but then you have to worry about layer styles scaling, but even then rounding layer styles to integers isn’t as bad as blurry vectors. If you want to finesse the scaled 2× version, you can, but even I have a hard time justifying subtle drop shadows at odd integers over simple even integer shadows. I feel that diminishing returns starts to set in, but Apple has started finessing some of their apps (Contacts in particular) in 2×.
Louie Mantia had a Dribbble shot about the pros and cons. I can understand the fight against blur, but to say that it’s “clumsy” is overblown. http://dribbble.com/shots/641997–2x
General icons are different. It may make sense to go big, then scale down. It may make sense to go the other way. It depends on the icon’s lines and the detail you want to achieve. (Think Mac OS X icons and not swiss minimalism.) Fragmentation on Android, however, has guaranteed that pixel perfection is an illusion. I would design for a popular device and serve blur to the rest.
Among the more popular posts written over the years on sub pixelation:
“About those vector icons” by Kirill Grouchnikov
“Designing for Retina” by Marc Edwards
“We’re in an icon-sharpness limbo” by Simon Samurai
“Pixel-fitting” by Dustin Curtis
“Your design is wrong (and here’s why)” by Mike Rundle