There have not been any specific rumors or reports about the RAM on the new iPads. As of now, all of the rumors and analyst reports indicate that the iPhone 6 will have 1 GB of RAM. iPhones and iPads have had similar hardware specifications in the past, but there's no guarantee that the iPad and iPhone will have the same amount of RAM (nor that the iPhone 6 will still have 1 GB).
I agree with s2mikey that the performance problems people complain about are software issues rather than hardware. We just made the jump from 512 MB to 1 GB with the iPad 3 and iPhone 5, yet the performance complaints seemed to come from people with the 64-bit devices with greater RAM (newer software, more bugs to be ironed out). iOS 7.1 made a big difference in memory performance. I would not be surprised if the next generation of iOS devices still have 1 GB of RAM, but we'll see what Apple does.