It is a leap, but not a jumping-over-K2 type leap. Basically, when you switch to protected mode you lose access to the BIOS. You can't do 'int 10h'-type calls to print stuff to the screen, grab keyboard input or read sectors from a floppy disk. You need to write device drivers for these things yourself!
That's a lot of work, and you can get bogged-down in tedious technical gubbins when you'd rather be doing something cool like making a GUI. This is why, in MikeOS, I've stuck to 16-bit: it makes the OS pretty limited but means the codebase is quite clean, and not full of complicated drivers for floppy drive controllers etc.
If you look around the osdev.org forums, you'll occasionally come across a keyboard, mouse or floppy driver that someone has written for the bkerndev kernel. That'll help you get on with the cool bits and bobs.
Last edited by M-Saunders
on Wed Jan 30, 2008 2:29 pm, edited 1 time in total.