In short: no.

The Spyder is supposed to create (a) an ICC profile and (b) a correction table for the graphic card.
re a) - color management aware applications can use the ICC profile.
re b) - the correction tables only work for the display attached to the computer's graphic card
The Spyder is "okay" to calbirate the display of your MBP ... but the MBP's display is of course not appropriate to color correct video / broadcast signals.

The Matrox Mini is connected to a dedicated PCI card (part of the package). Only applications that support the Matrox Mini (for instance Avid MC) can ouput video through the Matrox' PCI card ...
In other words: the Mini doesn't work exactly the same way as a second monitor for the computer, it rather works as a standalone monitor that receives its signal directly through the editing application.
Matrox however provide their own software calibration tool (on Mac it's installed in the system prefs).
It works quite well!
But, again, make sure the editing sofware you are using supports video output to the Matrox Mini.
Too, video out from the Mini is either HDMI or YPbPr component. HDMI to DVI convertors are NOT supported (unfortunately)... so you need a monitor that provides HDMI or component input.

Another approach is for instance the Matrox MXO2 (or Blackmagic HD Link). Those translate the computers DVI signal to a broadcast signal so that you can infact use your video monitor like a dual monitor setup. You can attach monitors with DVI input. While this approach works to some degree it has its limitations (for instance with regard to frame rates and viewing interlaced signals).

As to your last comment - I do use a Matrox Mini in conjunction with Avid MC. Not sure which feature isn't working as advertised ...?

/ So fcp7 doesnt support matrox mini out? /
due to the specs FCP7 does support the Mini: http://www.matrox.com/video/en/products/mac/mxo2_family/mxo2_mini/