(Edit - defeated by darkstorme and the "Fingers never stop typing" disease!)
I really think the reason this is going to a commercial venture needs to be better understood in order to understand the responses to your question - because it was answered the first time.
Yeah, for some becoming like WoW would be sucky, because "RP server" in most MMORPGs means "there are occasionally sporadic bursts of roleplay here and there." But we're not leaving NWN and going commercial because hey wouldn't it be cool if they poured even more time and money into Layo without getting a fraction back? Nor even "isn't it going to be great to provide all our players with new homes and even shinier things?" Because our players don't pay. While I sure they would love to carry over a strong RP base (I would think that perhaps steps should even be taken to give the current ones a 'try' at it in order to encourage it and set the stage for other incomers), really they're not going to have a clue how many people are going to migrate until it happens. How many have played here? How many have donated?
For one reason or another, most people cannot or refuse to pay for what is offered free. There are lots of reasons, and not just freeloading. We are seriously lucky that the servers are running right NOW. They could have been shut down a long time ago because preparing for a commercial game requires a lot of investment in time and money... and putting time (tons of administration) and money (server costs) into volunteer work is not top priority when everyone is also working day jobs.
This isn't about just making a happy new home for all of us, as much as they would like for everyone to migrate. They are also people that have all at one point or another put a lot of work and love into a project and then got the hope that maybe with even more work and more time they might someday be able to make a living off doing what they love, which is what everyone really really wants to do and few really ever get the chance. Even if it turned out to be a hack and slash server (which is as dependent on the players as anything else), becoming a commercial success at it means you can provide all the tools and encouragement possibly available to encourage RP... and you're still in the business. All they can do is provide the framework and advertise in the right places - it's always going to be the players that decide what is populating it.
I think becoming a commercially giant success with less RP is much less a worry for them than fearing they will cater to only a very small niche that will not attract enough people willing to pay to even come close to making up for the investment.
I don't want NWN to go away. I love NWN. I don't think anyone has even begun to bleed the game of everything it could have done. But even without the commercial thing, it was not staying. The NWN2 migration was in the planning before that changed - the playerbase moves on, the tools become obsolete, etc. But running two separate games just isn't going to work. Despite all the maybes and probablies, let's just be honest - the NWN server is not going to continue forever. It might bleed over into the launch and carry on a time, but I think we can probably be pretty confident that if they are giving ita good try for a year or more and it doesn't work, they aren't going to revert back to the now-even-older NWN to put their time and money back into it.
All of that rambled and said, I think orth's response might seem as though the stance bobby's question originated from is not a valid source of uncertainty for most of the people around and make the people that share the sentiment even more nervous about the ultimate goal of it. We've all played other games, new and old, and we all stick to this old thing because we find something here that does not exist in the other games...and it is that very vague and intangible thing that has always been more easily found in small labors of love than as paying customers; not because of the money but because of all the baggage that comes with it and the target audiences. So most of your players here are going to be biting their nails and just hoping and praying that whatever it is that makes Layo for them (the people) survives the move, in order to keep the niche audience and make it a financially feasible option for those that put the work into it. It is not unnatural for someone to have the hope that maybe if it's not we could keep the old toys, too?
But yeah, I think everyone should just think about it very carefully and instead of freaking out about it, really make it a point to migrate when the time comes and give it a good try for some time, even if it isn't liked at first... stick with it. This thing is clunky and old but the players make it a fun place to play and the people who bother sticking around to dev work for those who stick around as players. It will most likely be pretty rocky on first release and whether or not they want or expect everyone, the ability to start out with a base of people devoted to preserving what they found here should not be underestimated. They make the framework, all we have to do is be there. There will most likely be beta-hoppers wanting the trials and so forth going in and out if there are any, and people that don't know anything at all about roleplaying. But we have them here, too, in smaller, proportionate numbers. We just talk about helping out people and showing them what to do, so... make it happen :P