In terms of the Brewfest achievement, it's sort of a combination: you have to sample the monthly brew every month for a full year (October to September in this case). You can do this in any year, but with strings attached: you could only join the Brew of the Month Club during Brewfest, and after the month is out, you can't buy that month's brew anymore (so if you missed, say, December's brew, you're SOL until next December).

The objections are coming because this means, as it stands now, even if you do every other achievement to get the special mount, you still have to wait until the end of 2010 to get it.