Graphene is where silicon was in 1948 (the first transistor used Germanium BTW): basically nice in theory and very promising but many practical issues existing that prevented even lab prototype devices from being made. It wasn't even possible to make a reliable silicon transistor until the mid-to-late-1950s.
Will graphene be practical in only 10 years? It's a long shot because of current infrastructure and technologies: if it can't be made with existing technologies or interface to existing technologies (namely silicon ICs) it will be stillborn. To get from point A to point Z you need to traverse B through Y where these dependent on what already is.
An excellent historic parallel exists with GaAs which as being predicted to replace Silicon "real soon now" since the late 1960s! Still hasn't happened. In fact all III-V semiconductors (of which GaAs is about 50%) still account for less than 1% of silicon in both volume and revenue.
The other "real world" issue is the lack of capital to invest in technologies (even nice cool ones like graphene) because of the US financial crisis of 2007 and the current Euro crisis: R&D and start-up funding has been as rare as hen's teeth. The best funding source for any leading edge technology has been China (specifically the Chinese government) in the last 10 years.
Oh and without going to optical computer you will never get a 100 GHz processor - we hit a limit at 3 GHz because of electrical constraints unrelated to transistors themselves but due to physical limits of propagating electrical clock edges across a finite die size.
100 GHz is only possibly by shrinking the density and size down to a grain of sand (which probably keeps performance constant) or switching to some type of optical interconnect and processing (though it still may not allow processing to go much faster in sufficient throughput). The problem is that you quickly run into the same limit again even with light (the difference in speed is only 60%) so instead a more radical architectural change is likely required (i.e. quantum computer or non-Von-Neuman/non-Harvard computing: very out there!).
So I'm not holding my breath on graphene at this point (and I work in the semiconductor industry). I have my money on other technologies instead being more likely.