There's a lot of multipath-related work being done right now, at the IETF, within OpenWRT, and independently.
We've been working on providing multiple routes automatically (disclaimer -- I'm a co-author). As to actually making use of the multiple routes, the solution that currently works best is MP-TCP, a set of kernel patches that allows TCP to use multiple routes simultaneously, with no modification to applications. Other solutions are SHIM6, which works below the transport layer, and Multipath Mosh, which works at the application layer.
I'm pretty confident we'll be able to have most of this stuff enabled by default in mainstream Linux distributions by the end of the year.