SLRP means to slurp which originated from "dee slurper" (I believe from Letters) . . . It was originally used to describe all the 343 brown nosing and general defense-at-all-costs of Halo 4, but now it has been transformed into a term of genuine excitement about Halo 4 or acceptance of 343's changes.
The term gained popularity when kylej posted
this in response to slurpy Hydranockz post and it was hilarious. The 4 letter capitalized variant (which I can't figure out why everyone is using all the time) started off as an inside joke between Steelyuhas, Plywood and myself when we all changed our service tags to SLRP for a couple games of Rocket Hog Race and then joked about it here afterwards.