First was the Linux Standards Base, which made users of and developers for Linux servers and clusters able to depend on common interfaces and (to some extent) file locations.
Now, vendors are coming together to create similar standards for desktops and desktop applications. Oddly enough; the problems for desktop Linux were not a lack of standards, but too many and conflicts between them.
It is a step forward in gaining acceptance for Linux on the desktop. Just how much effect this move will have depends on too many variables to predict. Unless those concerned really blow this chance it will be to the good. The question is only how much.