Can you still return it?
You basically want to hold off purchasing anything camera-related close to March or September, since that's when most of the camera product announcements happen and often when rebate programs begin. Usually March, because of
PMA (although it was February last year). September because of
Photokina (in even numbered years; or just ramping up for the holiday season).
As for performance, the f/1.8's looking nicer. Here's the MTF for the 35/2:
And here's the one for the upcoming 35/1.8
If you don't know
how to read an MTF chart,
Nikon's (unlike Canon's) tend to only be done at wide-open performance, so all the data is of the first lens set to f/2, and the second set to f/1.8. This is likely where the performance is weakest, btw.
The horizontal scale is distance from the center of the frame. The center of the frame is at 0 (the left edge), and the distance from that is given in millimeters. You'll note that the FX-designed lens goes out farther, so you may want to ignore anything to the right of 15 on the chart for the 35/2. The vertical scale is the contrast modulation--how much of the light is getting through the lens. Air would be a horizontal line at 1.
The red lines are at lower-contrast (10 line/mm), the blue ones at higher-contrast (30 lines/mm). The higher up the chart the red lines are, the better the contrast of the lens is. The higher up the blue lines are, the better the subjective sharpness (resolution) is. The solid lines are Sagittal, the dashed Meridional (basically, diagonal lines in different directions). The closer the solid and dashed lines are, the smoother the bokeh will be. The flatter the line, the better the performance is across the frame.
Now, remember, this isn't the whole story. Chromatic aberration, flare resistance, distortion, etc. are not measured by an MTF. But it's certainly looking like the new 35/1.8 is a nice little lens.