They already have, go to Ebay and search for Android tablet. They have thousands, some white-label, some brand (like Archos). I have one with me right now. They range from as low as $90 to as high as $500+. The one I have was just under $200 with shipping and has a 9" screen. Just a tad smaller than the ipad, at less than half the price, and it is running Android. So I have access to the full array of applications as my Motorola Android phone, but in a tablet PC form factor. These are flooding out everywhere. I plan to get my wife and kids one each this payday. I think Android already took the market, we just haven't realized it yet.
Even if Apple cut their tablets in half, they can't compete with a $100 tablet computer. Not to mention the shear number of free apps on the Android OS. The iPad might be pretty, but most people out here still work for a living and are going to think long and hard before dropping $500 (plus the cost of the charger, etc.) for the iPad when they can get 90% of the same thing for 20% of the price. plus if I drop this or it gets stolen, I am not going to lose too much sleep over $200. I can't say the same about $500+ dollars going poof.