Each update and patch is a "new" version just as with software. Past the first printings the first content changes we got made it .X
My point is that we can't call essentials "4.5" because we don't know where in the lifecycle this edition is right now. It is simply 4.X and the current value of X is unknown.
And my point was that no matter how many "service packs" we might get it's still 4.x even 4.0 is 4.x because it's all compatible. When they rewrite from the ground up or stop "programming" the rules to be backwards compatible then we'll be moving on to 5.x starting with 5.0
This is actually a good point and a good place to extend my position. Continuing the software comparison there are two types of compatibility (forward and backward). Some may now be wondering what is the difference, well I'll tell you.
Forward compatibility (
Forward compatibility - Wikipedia, the free encyclopedia) is when you add something and an element of the existing system doesn't work right with it. An example of this would be how they have errated Melee Training. Without the update Melee Training works just fine as it is without any changes, but once you add in the new features it has some unexpected functionality which caused them to add errata for it.
Backwards compatibility (
Backward compatibility - Wikipedia, the free encyclopedia) is when you add a new feature to something and the new feature doesn't work right within the context of the old system. Everything in essentials (that I have seen thus far) is backwards compatible.
Of the two, forward compatibility is much harder to achieve which is why we are seeing a lot of errata to cope with features, that while they work just fine now, no longer work as intended given the new features that are being added (item and feat changes around MBA and Melee Training I'm looking at you). Do you need to play with this errata in your game? Not at all, unless you want to add essentials material to your game.
On errata there are other types of errata that are coming out. There is the change to MM which is completely unnecessary other than the fact that they want to appeal to lapsed 3e players with a power that uses the familiar name and works just like they'd expect it to work. I would hope we don't EVER have any of this type of errata, but we already know this is false.
There is also errata based on balance. As far as I'm concerned they can keep coming out with this as much as is necessary. Less is better in this case, but it keeps me from having to be the bad guy at my table. I can pawn it off on...but the errata says so (even if I think the player took it BECAUSE it was OP).
To sum up....some errata is good and some is bad and the difference is WHY they had to add the errata. MM was what I consider bad errata, and Melee Training I consider a good type of errata to keep expanding the game and adding new options.