I am currently in the process of moving away from Aperture and possible over to Lightroom. It is clear that I will loose at lot of the work that I have done in Aperture, if I will continue to have a non-destructive workflow. I don't mind the process of re-doing some of all this work but my question is. If I some time in the future will move away from Lightroom to which extent will I be able to maintain the work I have put into the non-destructive editing in Lightroom.
Most of my photos are raw format.
Unless the program you Move To, from Lightroom, can Read the edits placed in XMP files created by Lightroom (Or those edits written to the actual RAW file by Lightroom) all that work will be lost.
Adjustments made in one Raw file editor can't be read by some other Raw file editor. They all use different systems to make those adjustments.
What you could do is once you make all the edits you want on any Raw image file Export it to a TIFF file as a Master and never change that Master file. If you need to edit that Master or Raw file make a Copy of it first or once opened in a program like Photoshop select Save As and save it with a different name so the Master file is left as it came out of Lightroom.