I fear that any attempt to polish out scratches could damage the touch-sensitivity of the glass. This might render your iPad useless. Remember, the glass is not just a glass. It's also the input device for the iPad, your mouse and keyboard, as it were.
Using an abrasive to try to polish out scratches will certainly damage the iPad glass' oleophobic coating, which repels finger-oil.
Your iPad user manual states
Handle your iPad with care to
maintain its appearance. If you are concerned about scratching or
abrasion, you can use one of the many cases sold separately. To clean
iPad, unplug all cables and turn off iPad (press and hold the
Sleep/Wake button, and then slide the onscreen slider). Then use a
soft, slightly damp, lint-free cloth. Avoid getting moisture in
openings. Don’t use window cleaners, household cleaners, aerosol
sprays, solvents, alcohol, ammonia, or abrasives to clean iPad. iPad
has an oleophobic coating on the screen; simply wipe iPad’s screen
with a soft, lint-free cloth to remove oil left by your hands. The
ability of this coating to repel oil will diminish over time with
normal usage, and rubbing the screen with an abrasive material will
further diminish its effect and may scratch your screen
Scratches or cracks in the glass are expressly not covered by Apple's warranty, but it would not hurt to take your iPad to an authorized Apple service center or Apple Store and ask if they will do anything for you.
I believe your best bet is not to do anything to try to repair the damage, but rather to protect your iPad from any further scratches.
The way to minimize scratches in the future is to use a case or cover to protect your iPad, and to avoid carrying your iPad together with hard or sharp objects such as keys, pens, or scissors. Never leave your iPad lying around uncovered. Always cover it or put it in a case when it is not being held in your hands.
The Apple Smart Cover for the iPad is a valuable investment at US $39. I think they are indispensible, and that everyone should purchase one along with an iPad.
Of course there are a huge range of custom covers and cases you can purchase from third-party companies.