"does it really matter if u have this motionplus" - did you mean "does it matter if there is a pass through for the Nunchuk if you have the motionplus" or did you mean "does the motion plus matter"? If the first, it does matter for those games that use the nunchuk, the motionplus doesn't do anything the nunchuk does. If you meant the second, motion plus apparently matters a lot for those new games that will use it (such as Tiger Woods and Grand Slam Tennis), and not at all for past games or new games that won't use it.
In theory, a great FPS can be had with a Wii Remote with MotionPlus and a Nunchuk. You can have the Nunchuk stick do you forward/back and strafe left/right, and the Nunchuk's move sensor to turn left right, and then use the Wii Remote with MotionPlus to aim your weapon. I can just imagine a very immersive sword/weapon based game with this, a Jedi game that has this ability, I would definitely buy!
Didn't Nyko already do that? Wii Kama Wireless Controller (Colours May Vary) Just plug their wireless nunchuk adapter into the Motion Plus and you should be good to go. But I get your point that again it's one more freakin' added expense