I've never once had an issue with the cord connecting the Wiimote and Nunchuk, well not after my little Wii Boxing incident..... Moving on...
Though a wireless Nunchuk would be great for comfort, like Kiryllos said sitting back on the couch with my arms stretched out without the cord trying to strangle me does sound appealing and storing 4 wireless ones as opposed to normal ones would make my table look a lot neater.
Though if they need their own batteries on top of the Wiimote, I think I'll have to pass, I've gone through 30 AA batteries since I bought my Wii four months back. Not to mention my wireless mouse on my computer and various other battery powered appliances around my house.