I've finally gotten the chance to check out a 2013 catalogue, and noticed some sets released not that long ago not being featured. For example, the ambulance no longer advertised while the dirt bike transporter still is, no forest police station featured, and no The Zombies on the Monster Fighters page. Does this means that these sets are going EOL? Any thoughts guys?

I'm on the fence here - I think the catalogue is a sign of which sets are being heavily pushed, but I don't know that an exclusion is necessarily related to a product being EOL. I wish it were that simple!

I'm with Veegs. I once thought (or maybe hoped) that the catalog was a look into the near future, but history has shown that it doesn't work that way. The LEGO Group is smart. It is no secret to them that a lot of people want to know when sets are going to retire. I'm sure they do everything in their power to avoid giving tips on what is happening. They do their best to keep us guessing.

Well, there are certain sets retired from previous years. The whole City Airport series is now retired.

The Lego catalogs almost always have the DS and any other SW UCS sets, and I haven't seen any signs of the DS retiring soon. :(

The ambulance set shows retired on the lego website. 4202 the mining truck is also already retired according to the lego website. The tipper truck 4434 is also retired. If you plug the number into the lego site it tells you retired on some of these.