The first question is partly answered via the choice of operating system. If the tablet runs OS X iPhone, it will be considered a big iPod. If it runs OS X Snow Leopard it will be considered a Multi-touch Macbook.
The same goes for the name. It will be either iPod Pro or Macbook Touch.
However, if the Apple tablet features a middles class OS X, then the name is up for grabs.
It still depends on how revolutionary is the new software. If it resembles a Macbook, it can just be called Macpad.
However, if Apple plans to redefine the product class similarity as it did with the iPhone, the new device may as well be called an iBook ( a name Apple has already used for a consumer type of notebook before the Macbook)
Apple switched to Mac in its laptop line when it switched from Power PC to Intel architecture in 2005. However, ever since WWDC 2008 it dropped Mac from its OS name as OS was now running on iPhone as well on Macs. Back in 1998 it used to put Power in front of its Pro products and "i" in front of its consumer products. Ever since 2005 the name iBook has been seeking its new product.
So the logical choices are:iPod ProMacbook TouchiPad (entry level tablet)Macpad (bigger tablet)iBook
If Apple introduces several classes of Tablet products and especially an upper class in the $1000 range, it may as well drop the current Macbook from its product line up as it is Pro in software but consumer in hardware and it is an old design.