Here is the news straight from Archie Comics.
Starting with issue #600, there will be a six part story titled “Archie marries Veronica.”
Issue #600 is part one, “The Proposal.”
The cover art shows Betty standing outside the jewelry store, where Archie is on one knee and Veronica is saying “Yes!”. Betty is clearly crying and yes, you Hooper X fans out there, Jughead is outside too and he looks a little broken up.