The new iPad…
1. It’s not lighter.
2. The battery doesn’t last longer.
3. The screen’s the same.
4. It doesn’t have more RAM (well, maybe it does, but we won’t have confirmation until it ships).
Okay, sure, it’s faster, but if you have an iPad 3, it’s not really that much of an improvement, especially if it doesn’t have more RAM. So, unless you’re really excited about the lightning port, enjoy your iPad 3 until they can make it lighter.
That said, if you have an iPad 1 or 2. Retina, man! It’s awesome.