GameRager: Considering all the free publicity that community modding brings to a game series and it's publishers it's probably a likely bet....for PC versions anyways. Since most DN3D fans were also into the modding scene i'm betting more are buying the pc version in hopes of getting their hooks into any possible modding tools as well as avoiding any consolitis or dumbing down the console versions might possess(one being lower res. graphics prolly)
Only Bethesda have shown they understand the goodwill they recieve from bundling modding tools (good ones). There are over 9000 mods for Oblivion and Fallout 3/NV and yet they also enjoy excellent sales of DLC.
However most publishers seem to think modtools that allow people to make free weapons/armor etc can hurt DLC sales. Especially when the publisher wants to sell weapons/armor ala Mass Effect 2. We aren't getting mod tools for Dragon Age 2 and for that reason it's going to remain a broken mess but you can bet EA will have lots of alternate appearance packs for you to buy with Bioware (tm) points.
Never assume we will get modtools. Publishers hate them.