I doubt it.
First of I have seen arguments that try to make difference between desktop OS and laptop OS. So lets make it clear:
Desktop operating system is the main control program in a user’s desktop or laptop computer, also known as client operating system.
from
https://sites.google.com/site/operatingsystems10/home/desktop
However for the sake of argument let's stick for a moment with computer tower: is FreeBSD suitable and have it future as desktop/tower OS?
If you understand desktop OS really narrowly: I can run some stuff on my carefully selected hardware then answer is yes - FreeBSD will manage somehow at home.
However this is not what defines desktop OS in general:
I have several computer towers connected to very specific hardware: confocal microscopy, sequencing hardware, PCR, Western, and bunch of other hardware. None can be managed from BSD, linux, OS X. Form most part specialized hardware is not accessible from anything else than windows.
In fact situation worsened as some time ago a lot of diagnostic hardware had UNIX interface. Not anymore.
At home: sure but only if hardware is carefully selected for compatibility (which excludes from FreeBSD a lot of latest laptops). Even at home I need windows in VM because all photo editing software that I use is not available either for BSD or linux.
The only hope for home unix desktop os is the expansion of web applications which can alleviate some of the problems, but not all of them.
I have been using BSD since mid 90' I did use SunOS, Linux, Netware, MacOS, Windows and Be. Since VirtualBox 4.x I don't have windows installed as main (dual booting) OS but I still need Windows for some stuff. This makes BSD/linux a fringe/enthusiast desktop OS and this will stay this way 'til the time when OS will not make that much of the issue.
BSD and linux future is in the server land as desktop OS not so much unless the only use is browsing, email, music, some video streaming and a bit of document editing excluding any specialized desktop software.