excuse my inexact quote, its more the memory i was trying to share which seems to of worked.
Its true to say an entire rewrite is not a port - again im sure you've spotted the tongue in cheek attitude of my previous post. Porting is, specifically, moving software from one platform to another. This is rarely done just by changing compiler options however except with (arguably) the best written code. Code is said to be specifically portable when the time it takes to convert parts of it to make it work on another platform is less than the time it takes to rewrite it.
DBP code is often not much of a chore to port to DGDK depending on its complexity. Porting DGDK to XNA based code (assuming the xbox c# implementation) is an extremely daunting and unlikely task - a bit more probable is converting DGDK-NET code to XNA supposing c# was used as the enviroment for DGDK-NET. Again, horriable - unless you have a wrapper ready or are willing to write one to aid all future porting between platforms.
For example I once wrote versions of DGDK's 2D functions for the gp2x (linux/arm9 target). It didnt take as long as i thought either (3d would of been more complex) and at the end i had a library of 2d functions (and input functions and half the file functions) ported for ARM cpus using an sdl layer (for the most part anyway). dbLoadImage() was replicated with dbxLoadImage() etc etc and enabled me to very easilly port pure 2D games i had written in dgdk to the gp2x (and even any linux based) platform. Guess it just depends what you're willing to do to get the job done
The good thing about a wrapper of course is you only have to write it once.
But yeah, bit contrived and going off topic I guess, if there even is a topic. But yeah, whatever.
edit: confusing typo