Will it form a triple bottom at around -1.5, or going to make a new low? It never goes below -1.5 in the past 3 years
I would say it will go to a new low (but not a lot lower), probably the exchange rate will stay around here (300-200) for a little longer (march 2015), then slowly will start to raise.
There are external factors slowing down the increase of the exchange rate independent from Bitcoin adoption and Bitcoin inflation rate (new coins mined).
In particular, the MB creation by the Federal Reserve is near zero and the M1 is a good 3-5% lower than Bitcoin inflation.
If we take in account the zombie-coin (Bitcoin not moved by one year or more) the inflation rate is a lot higher.
Until the new adopters convert in Bitcoin more than $ 1.3M/day in goods and services (net of all imports in and exports from Bitcoin), the exchange rate will not recover. 1.3M/day is just to keep up with the current exchange rate.
New adoptions from merchants and users could increase the demand to hold a few times (now there are a lot of way to spend Bitcoin, so many could also be paid in Bitcoin (at least partially).
Every merchant is also an adopter and could pay its suppliers (of goods and services) or employees in Bitcoin or be paid in Bitcoin by another merchant accepting Bitcoin (E.G. Dell could pay Microsoft with Bitcon for the Windows licences included in Dell's Computers, so could have an interest to pay keep a balance in Bitcoin to do so - Overstock sell Dell Computers and could be paid in BTC and pay Dell with BTC).
Microsoft could pay some employees in Bitcoin and these employees could buy something from Dell or Overstock.
More BTCs start circling and never need to be exchanged in $, less will be available at the exchanges. Less will be sold at the exchanges, less $ (in fiat or goods and services) need to be converted to keep up the same exchange rate and the exchange rate start to raise.
The effects of adoption of BTC by Microsoft will be see in the future. If Microsoft aggressively deploy the payment system for all international services and goods, and it have the same trend of Overstock.com, we will see a 0.05% revenues initially ($4M/month) growing to 0.1% (in the first quarter) and 0.25% (in the second quarter) and around 0.5% in one year (this is a not trivial 240 M/year). 1% of the MS revenues are what is needed, alone to keep the exchange rate at 500$. If Microsoft start paying employees and suppliers with the bitcoins it receive this will bust up the price a lot. If this do not happen, the price will not be pushed up much.
Until the next halving, long speculators will speculate adoption (the utility to adopt Bitcoin) will trump inflation and short will speculate inflation will trump adoption.
After the next halving, when inflation rate go at <5% per year level, Bitcoin will become interesting as a way to save, because inflation will be way lower than in $, £, €, yen, yuan and whatever.
Then things will become interesting to observe. We will see a lot of currencies die. Very fast, very painfully.