Red Jason wanted to hear what I thought about the latest article on monster design, straight from the fingers of Mike Mearls and Chris Sims. If there's one thing that gets me rolling for hours its talking about games and game design, so of course I was all too happy to oblige.
As a veteran D&D gamer, I remember trying to build monsters since 2nd Edition, which really had no guidelines that I could recall. You kind of just did it and then...whatever. 3rd Edition went a long way in providing some kind of organization to the whole process, but I found it extremely difficult to build even basic monsters since you were basically building a somewhat simplified character. Sure, you can half-ass it and just write out some basic stats for the stuff you need, but if you wanted to do something official it can get pretty complicated (especially if you start adding classes to the mix).
Also, there were issues with trying to make monsters of certain types because to make them challenging for a given level you really had to rack up the Hit Dice, which caused other problems with stuff like save DCs for their attacks, feats, saving modifiers, and skill modifiers. The vermin type comes to mind, with its lowly base attack bonus.
4th Edition really streamlines the entire process while ensuring that your monsters are all balanced for their level. Its very easy to make a monster, even on the fly. Heck, the tables for damage and the page 42 table is on the back of the Dungeon Master's Screen. Paste a simple level formula for monster attack bonuses and defenses and you can go pretty far without cracking open the DMG. I threw a Large fire beetle at my group in Siege on Bordrin's Watch, which I threw in the encounter on a whim with no stat block handy at all.
The provies some basic yet useful advice, and most importantly explains the purposes of each monster role. You even get a few tips on elites/solos and healing powers (read: dont use them). Short and to the point, its a good read even if you've been kicking out monsters before 4th Edition was even released. These are the articles I like the most, as we get to see how things went from start to finish from the designer's point of view.