At the moment retina display is very very overrated. No developer is taking the advantage of the new display, all these blurry icons are really pissing me off. If there aren't more apps updated in about 30 days I'm seriously considering returning my iPhone 4 and getting a 3GS. I don't know if it's worth it to keep the new phone even though it has more ram. That's about the only positive so far.
FYI its not as easy as "updating the app". You have to recreate all of the artwork, from scratch, at four times the resolution. That is a LOT of work.
Not to mention, you can't just make a larger version of the art work and scale it down either and have it look nice on both platforms. For some images this may work but certainly not for all, especially images with a lot of fine details or linework.
Give developers time, there is a ton of work involved in creating an application.
-Dev's only had roughly a week to start submitting iPhone 4 apps. Without the hardware to test on, its a gamble to see if your graphics show up correctly even when using the iPhone simulator.
-Apple usually takes about two weeks to approve an app once submitted, and being a ton of developers want to release their iPhone 4 apps I'm sure its a bit backlogged.
-The GM seed has been out for less than a month. For a lot of people, this is the only one worth trying to make your app compatible for because if you change everything around to guarantee compatibility on any previous seeds, the next seed may break it.
Please, before you come acting all ridiculous please do a little research and realize making apps, even the most simple ones, is not an easy process.