@slrandall
I can confirm your issue:
I am now using a rMBP 11.3 (Mid 2014) with OS X 10.9.5, and previously used a MBP 2.1 with OS X 10.6.8 (Late 2006).
I too noticed that when running compiled Applescripts apps that were compiled on my non-retina MBP that they use non-retina resolutions and thus are blurry.
There is no apparent fix within AppleScript or other native Apple Software:
I tried to recompile them with the current Applescript Editor (Version 2.6.1 (152.1); AppleScript 2.3.2) as apps, but they still only remain non-retina.
But luckily there is a fix with a 3rd party freeware:
http://retinizer.mikelpr.com/ successfully scales up standard UI elements and fonts to retina resolution of any app dropped on it.
The process is non-destructive on the dropped .app bundles, but just creates an entry in a separate registry.
Apps can be individually "retinized" and de-retinized", or you can choose the global "retinize all apps" (on my Mac).
As Applescripts use mostly (or completely?) standard UI elements this is an acceptable fix for now.
@Apple:
It is desirable that Apple's own software should support all its hardware features out-of-the-box.
Please make AppleScript Editor compile retina compatible apps.
(Maybe fixed in Yosemite? Confirmation anyone?)