One of the points of the ones who promote P2P connections is the limited bandwidth that present PON technologies offer.
Although I always say against this point that once you deploy a PON the bottleneck is rarely on the PON but on the aggregation link, I must admit that the potential of P2P in terms of higher bandwidth capabilities.
In any case, at present 10G PON systems have already been standardized and also WDM PON is on its way so I believe that a good upgrade path for PON outside plants is to migrate, whether to 10G or to WDM PON.
Each of those technologies have their own advantages and disadvantages but none of them have practical applications at present but in very specific cases. At present they are too expensive for a massive deployment and therefore, limited to trials or for a very reduced number of users. The cost, specially at the end user side is simply too expensive to make them economically viable. In any case, this will change in the mid term.
Once WDM PON becomes cost effective, P2P and WDM PON will be heavy competitors because WDM-PON will be able to offer the same bandwidth capabilities than P2P and the cost of the outside plant will be reduced. Anyway, I also believe that P2P has a lot of potential, specially in greenfields and places where ducts are available.
At the end of the day, it just a matter of encouraging FTTH.
Next week I will explain WDM-PONs in detail.