Unfortunately, I don't believe there is time to properly test and incorporate merkle tree pruning before we need to increase the block limit, but that should be a focus as well as using invertible Bloom filters .
http://www.coindesk.com/juniper-research-bitcoin-transactions-double-2017/A couple years according to these researchers. Double our current average and we still aren't at 1MB.
It is the upper limit peaks which are problematic and preparing for the future before the next traffic increase along with other decentralized apps like lighthouse being restricted. We are already seeing full blocks from time to time at the moment, thus we should be concerned now.