Vanessa et al,
Sorry to hear about your disappointment, however I think it is one of the better freebie T's I've had. (The best so far was a cotton one from a Coventry Half in 2008 that I still wear.)
May I suggest that you look at the TV coverage of the event and notice the demographic of those running. One size, (which I reckon must be a generous large), was a good decision for an organiser that needs to satisfy the potential of 37,000 finishers.
You may well be disappointed,( as I usually am when I finish an event with multi size T-Shirts to find out that there are no more XL's left), but I think the majority will be more than happy with the VLM2012 finishers shirt.
Why do most events run out of the larger sizes? Because they are the most popular and even those that would normally take a smaller 'technical shirt' size realise that after the first wash an XL becomes a M.
What an embarrassment it would have been to wear a Finishers T-Shirt that was too big for you!!! However I thought it fantastic that I was able to wear mine afterwards to the Hard Rock Cafe for a full rack of ribs and accompanying beer. Come the end of the week and the time when it gets taken out of the ironing basket, I'm sure it will be joining the countless others in my car polishing rag box

p.s. This will forever be an ongoing argument and is covered after most/all events.
Even the GNR that Neuv says have it right, get caught out. They run out of the larger sizes because, when entering, people say they want a medium but come the end take a larger size !