Not by default.
What you can do is montage the images into a single image of two long rows -tile x2
You can then tile crop this into 4x2 images (when you have worked out the montage tile size)
http://www.imagemagick.org/Usage/crop/#crop_tile
The last image will be 3x2 images.
However the order of the images will be to put the first half of the images along the top row
and the second half along the bottom, without any regard for the division of the images.
Another alternative which was just worked out is presented in
http://www.imagemagick.org/Usage/montage/#columns
This montages the images into seperate columns (in your case pairing the images in columns of two)
You then use a second montage to collect the columns into lots of 4 and trim the unused columns from the
last image, OR just create again one long image (horizontal append) and tile crop this into sections.
Basically which method you use depends on how you want the images ordered in your results.
There are many ways of doing it, and in the future we may have a set of 'layout' operators that will make it easier.
In the mean time you will need to DIY it in some way.