I don't want any decision done based on such speculation.
Finally someone else agrees with me that we should not be basing the implementation/solution on speculation. This is exactly what Gavin has done and it is way too risky. We can not know what will happen in the future, nor will the past trends continue.
However, there are concerns raised with potential gaming of the system and manipulating the size by pushing extra transactions. Doubling may be excessive, so a lower percentage may need to be considered. It should also be noted that BIP106 only considers the demand for block space and doesn't take miners' resources into consideration, which could potentially impact decentralisation if not kept in check (but again, changing the doubling part to a lower percentage would help in this regard).
I concur. The main thing that bothers me is that instant doubling and halving. I think that this is way too much especially in the long run. Going from 60 to 120 MB blocks seems like way too much. If a lower percentage is to be used then this proposal would be much better.
There's also BIP105 now, and it proposes a maximum 10% increase or decrease every 2016 blocks.