I've just realised I'll need to plug an HDMI lead into the back of the TV for the wii u. For now I can unplug my PS3 but this is only a temporary solution. I already have one splitter in use and I'm wondering if another one in use will affect things or will it be ok. It would be useful if I could buy a hub similar to the ones you can get for usb for using with a pc.

Maybe something like this....you plug all your devices into a hub and then the hub into your TV.

http://www.amazon.co.uk/Duronic-HDS3-Switch-output-Switcher/d...

This was just a quick search so you might find something cheaper around as well....

I got one from Monoprice. Don't know if they ship outside US though.
http://www.monoprice.com/products/search.asp?keyword=hdmi+switch

Brilliant thank you. I thought I would have to get rid of one of my toys.

I picked this one up: http://www.tvcables.co.uk/cgi-bin/tvcables/hdmi-switch-3-way-... seems to do the job for Wii U.

You could also get an inexpensive home theatre receiver. As a bonus you'll get better sound and the potential for true surround sound.