In light of recent online issues, Xur's stay in the tower this week will be extended until at least Monday night at 10 PST. Depending on how the networks look, Xur's visit could potentially last even longer.
Full information from the Destiny forums -
"We understand that Xur has been hard to reach for a lot of you this
weekend, so we’re going to extend his stay. Our current plan is to allow
him to remain in the Tower with his current inventory until Monday
night at 10pm PST, just before the weekly reset. We’ll also keep an eye
on the overall situation, and prolong the extension, as needed, for as
long as is feasible.
Next week, Xur will return to his regular schedule, with refreshed inventory. "
So if you really wanted something from Xur this week, fear not, as it looks like Bungie is attempting to let you spend your hard earned coins.