The ltle bk of txt msgs (published by Michael O'Mara Books in Great Britain in the year 2000 (or Y2K)) lists lol in the third Chapter entitled WANT2TLKFST? (Want to talk fast?).
The entry for lol states:
"lots of luck or laughing out loud"
The usage of lol for wishing someone luck seems to have rapidly declined and remains solely for the purpose of laughing out loud.
gl is the acknowledged abbreviation for wishing someone luck - standing for "good luck".
Why, given the opportunity to choose, people (or ppl) still insist on laughing out loudly is one of the paradoxes of the post-modern age.