Or, that's what it seems.

The id Tech 5 engine uses 'MegaTextures' - huge texture maps (up to 128000x128000 pixels) that require huge amounts of preprocessing to create.

id - and John Carmack in particular - are still very much pro-modding and have confirmed their plans to eventually open-source id Tech 5, but are unsure if there is a way around this technical limitation. Simply put, it is unlikely that any modder would have the computing resources that are required.

So the Tech5 engine is going to be some massive graphically amazing engine, that we can't mod. And Quake 5 is going to be on this thing (Assuming we get a Quake 5).

That means there can't be any mods, so Quake 5 multiplayer has to be 90% perfect out of the box for it to be played seriously.

Why do I see this as a repeat story of Quake 4?

Maybe they'll shock us all and make it amazing. But, things like this don't make it seem probable.

Oh well, we have Quake Live.