'Lost' has already been officially connected to the TV Universe, thanks to Oceanic Airlines (mentioned in 'Diagnosis Murder', 'JAG', 'The War At Home', and 'Alias'), the music of Driveshaft (heard in an episode of 'Alias'), and the UK version of 'The Office' (the father of Charlie's girlfriend was going to buy a paper company in Slough in a flashback).
But here's the linchpin that makes its connection solid - in last night's episode "Flashes Before Your Eyes", a Playpen magazine was seen in Sawyer's stash while Charlie and Hurley were rummaging through it.
Playpen is the go-to gentleman's girlie mag when you want to suggest Playboy without getting into any legal hassles. And it's been seen in nearly a dozen other shows in Toobworld (including one set in the Tooniverse):
'Homicide: Life On The Street'
'In Case Of Emergency'
My memory being what it is, I've probably even forgotten a few to add to the list.
As I mentioned, 'Lost' is already an official part of the TV Universe, thanks to 'Diagnosis Murder' (which connects to 'Mannix' which connects to 'Here's Lucy' and from there it explodes wide open). And as far as Toobworld is concerned, all shows are in the mix; we just haven't discovered all of their official links yet.
But it never hurts to have another anchor. Especially one with fold-out nudie shots!