I've been watching some of the Robo-One competitions and am really amazed at what these little guys can do. I realize these bots are slightly more complicated in their programming (balancing, for example, requires some finesse) and have more servo motors than the basic retail kit, but I can't stop wondering what an NXT version would look like.
Given the size and shape of the NXT servo motors, I think it's safe to say that a NXT Robo-One competitor would be slightly larger in size. I haven't dug too deep into the rules, but I imagine there are maximum and minimum height/weight requirements (if anyone knows more, please comment).
A bot like the Robonova-1 has a total of 16 servos. Given that we will be able to buy individual servos from LEGO for under $20US, I don't think it's completely impossible for us to expect some individuals to purchase 13 or more servos and build a "NXT-One."
One of the biggest costs for buying and/or building a custom Robo-One competitor seems to be the machining costs involved in building the framework to hold all those servos - add in the cost of the software and the servos and you've got a pricey little bot. The ready-to-assemble kits float around $750 to $2000 or more (Robonova-1, Lynxmotion, Kondo).
Now, let's tally up the costs for the NXT-One:
Basic Retail Kit: $250US
13 additional servos: $260US
There will be some other costs not listed (such as extra cables), but the biggest expense are the motors. The framework would be built from the basic Technic beams and misc. parts. If the NXT-G software can't handle the programming requirements, there are plenty of free options that are available now or coming soon. But I think it's very reasonable to see a few bi-ped bots designed using the NXT system showing up soon...
Now, are there potential problems? Sure.
The cabling for the NXT sensors and motors are thick and not so flexible. Easy to fix? Absolutely - I'm sure users will figure out how to create more flexible cables, not to mention third-parties offering different lengths and thicknesses for the cables. LEGO may have options in the planning as well...
Size is definitely an issue. If you figure 1 servo for foot, ankle, calf, thigh, waist, shoulder, bicep, and forearm (x2 for 16 servos), you've got one very TALL bot. Take a look at the example Robo-Ones I've linked to and you'll see that most of these servos are small, square, and fairly compact. So we've got the issue of the NXT motor size and shape to deal with. But LEGO builders are a creative bunch, so I don't anticipate this being a problem for too long.
Balance - I've seen NXT bots now that balance okay on two legs... but the steps taken are small, and some could be considered sliding rather than true walking. This will most likely be a software issue - how best to shift the weight/center-of-gravity of the NXT-One to keep it from falling over.
Bulkiness - It'll be interesting to see how few parts can be used to build a solid framework for keeping all the servos linked while at the same time reducing bulk and keeping the bot looking "human" in shape.
Other issues? Please comment...