I have an old NXT (or NXT 2.0, do not remember exactly) bought I think in 2007. I would like to upgrade to EV3, but I am not sure if I should buy the complete set or only the central brick.
Is there any news about a possible new programmable brick in the near future?
Since the NXT 2.0 was released in 2009 you must have a first generation NXT set then. As per this question the peripherials (motors, sensors and of course their connecting cables) remain compatible. So you could just get the central unit and use the already owned NXT components. Keep in mind though that all parts (motors, sensors) have since been redesigned, so the EV3 versions will likely work better, and don't forget that the EV3 set includes an infrared sensor as well, which was not present in the NXT complement.
From financial point of view it would be more cost effective to buy a single EV3 brick. However these are rarely sold alone and the price for extra parts could be negligible if bought as a set. It might be easier to find a good deal for a set as well.
It is hard to say if LEGO is looking to release EV3 successor. However LEGO has released a new series of powered electronics as they call them "Power Functions 2" or "PowerUp" with pretty much same specs as previous series, but with new type of connector. This connector is very close to one used with EV3, but different. The whole range is designed to be used with basic robotics system (Boost) as well as general consumer sets (Trains), basically making it one-fits-all. So there is some hope we might see proper robotics system in not so far future.
