I'm going to throw out two predictions for later in the year (May-June 2016). These are pure speculation on my part, please take them with a large grain of salt.
1. Zero FX and Zero S/DS ZF9.8 will get the interior permanent magnet motor upgrade.Currently the FX and smaller S/DS bikes continue to use the older motors. The smaller S saw a $1000 price cut vs 2015, but the FX stayed at its old price.
I don't believe the bikes retained the older motors for cost reasons. Indeed, the FX and FXS are at the same price point
despite the FXS IPM motor; I assume that the part cost to Zero is very similar between the two motors. These two bikes - the least likely to benefit from improvements in high-speed/racing heat dissipation - will be used to
clear out existing inventory of the PM motors before switching all bikes to IPM. It also gives Zero a small upsell for the four-brick S and DS bikes. The switch to IPM may happen prior to any announcement, ie someone purchasing a bike built slightly before the announcement might happen to get an IPM motor .. just based upon Zero's inventory levels.
Switching all motors to IPM will also reduce the number of parts Zero needs to stock and test. I assume the motors are drop-in replacements, so eventually service replacements will be IPM motors (including for 2013-2015 bikes).
2. All bikes but Zero S/DS ZF9.8 will get a price cut in mid-2016 .. probably $1000.When Zero launched the 2014 bikes, Zero
dropped the price of the S and DS bikes by $1000.
As a result of the refined model offerings, the price of the Zero S and Zero DS models have actually come down by around $1,000 as compared against the 2013 lineup.
When Zero launched the 2015 bikes, the price increased across the board by $350 ...
By staying focused on carefully selected motorcycle categories, Zero has kept their product line diverse enough to meet the needs of a wide variety of riders and lean enough to offer customers refinements without substantial increases to suggested retail pricing. As a result, the premium upgrades to the 2015 line will only cost riders around $400 more for very significant improvements.
... but on May 20 2015 Zero
cut the prices for all bikes by $1350, giving the 2015 bikes an effective $1000 price cut across the board too.
Seeing its battery costs fall and energy density increase faster than anticipated as it develops successive model years of high performance electric motorcycles, Zero Motorcycles has decided to deliver this increased value immediately to consumers in North America.
The mid-season bump had the effect of giving them some good press and likely a decent sales bump later in the year, while the higher prices early in the year allowed them to capture a little more profit from the enthusiast base.
I expect Zero to do something very similar this year. The initial $1000 price cut on the Zero S/DS ZF9.8 gives them a talking point regarding continued price cuts, without cutting into Zero's profits; the FX and the four-brick bikes have always been Zero's bread and butter. The price cut on the three-brick bikes lets them market to a slightly more price-sensitive segment and bring interested riders in the door, and the sales mix will give them some early signs as to reception for a later price drop.
The IPM motor and the number of bricks in the battery is the only real difference between the three and four-brick Zeros, and per the FX/FXS price parity the IPM motor must not be hugely more expensive. Zero doesn't really
provide a specific reason for the price drop of the three-brick Zeros, which is a good indication that it's a somewhat arbitrary price point.
As innovations enable the motorcycles to go farther and faster, investments in technology make them easier than ever to own, a key part of Zero’s strategy to bring more riders on board.
I think this strategy is pretty smart on Zero's part. It allows both Zero and dealers to capture larger early profits from the somewhat less price-sensitive enthusiast base, and then later in the year a price drop can pick up sales from interested newcomers who were perhaps turned off by the price of the higher-range bikes.
TL;DR I expect Zero will bring IPM motors and match the $1000 price cut on the ZF9.8 bikes across the board in mid 2016. Unless they don't. 
