I think abbreviations become words once an actual pronunciation has been assigned to them so they can be modified as other parts of speech. Words such as "scuba," "radar," "sonar," etc began their humble beginnings in the English language as acronyms and graduated to nouns so as to facilitate pluralization. "Lol" has apparently been graduated from an interjection to a verb so as to allow for conjugation (I lolled, you lolled, he/she/it lolled, etc.)
Perhaps this is a bit OT, but I feel that this is exactly why English is not the defacto language in the U.S. It's not so much that it is not the preferred language, but rather constantly evolving from generation to generation. IMHO. (in my honest opinion)