One possibility would be that Apple will drop iPad 2 together with iPad 3 (the new iPad), and replace them with a revised, possibly 4th generation full-sized iPad, so that we will see two lines of iPads: full-sized and mini, and no more two kinds of full-sized iPads, one being cheaper than the other.
My reasons are based on the circulating rumors of the imminent release of the mini, and, more importantly, that the new iPad was Apple's secondary plan as the replacement for iPad 2: it has the lowest profit margin due to its high production and component costs, which were forced upon Apple due to the lack of adequate technologies at the time of release. I don't see Apple retaining the new iPad line as it is, just to make it a cheap alternative to the next generation iPads, especially when considering its already small profit margin.