I have emailed Tesco regarding KitKat for the Hudl and this is thier reply:
Thank you for your question regarding the Hudl.
Our development team is currently investigating the possibility of installing KitKat on the Hudl.
If you have any more questions, please do not hesitate to contact us again.
Tesco Tech Support
Hopefully we will see some KitKat goodness for the hudl soon