Apparently A Release Candidate has been sent to Vivendi (HL2's Publisher).
For anyone that doesn't know, when the developer (Valve) has finished their product (Half Life 2) a Release Candidate of said product, is sent to the publisher (Vivendi) for approval. If the publisher is happy with the product then it is sent to the printers. Otherwise it is sent back to the developers with a report on what needs altering or tweaking before the publisher will permit the product to be launched.
This whole process goes with patches too, and sometimes the publisher can be very stubborn at this stage. Even to the point where the Publisher to Developer relationship is severely strained.