The development guys over at Valve are blogging about the development of Team Fortress 2 on the official TF2 site. The following is an excerpt from the blogs

(Valve) - That's what I'm talking about!
January 27, 2009 - Robin Walker

We're just about done with the Scout pack, and our design and coding has already moved on to the next pack. The weapons and achievements are all nailed down, and we just have to finish up the final artwork on them. We like to do the final art as late as possible to ensure that we don't waste any work, which turned out to be a good decision this time around due to the large number of unlockables we tried out as alternatives to the Scattergun. Balancing his replacement weapon has been very tricky due to large threat difference of the Scout between skilled and non-skilled hands. More on that soon.

In the meantime, here's a few answers to some questions we get regularly:

"When's the next update going to be out?"

We've got an update that should be out tomorrow with a bunch of bug & exploit fixes. Later this week we hope to have another update out that changes the way we store your unlockable items. You shouldn't notice much difference, other than if you play on multiple computers we'll now propagate your item choices. You can think of that update as the one that moves your inventory into the Steam Cloud. Once that's out of the way, we'll be able to ship the Scout pack.


"Why did you change the minigun's muzzle flash away from the original one shown in Meet the Heavy?"

That muzzle flash was one of the earliest effects that we put in the game and it was done before our new particle system was in place. As we moved forward with the effects we decided that such a cartoony hard-edged look to the effects didn't help the readability of the overall game. If the muzzle flashes and all the effects had well defined edges, they would visually compete with the rest of the TF2 world and the players. So it was decided that the effects should be much softer than the rest of the game so as to not overwhelm an already visually dense game.

The remainder of that blog can be found here.