Let's see what they could pre-load:
#1 Linux
#2 OS/2 or eCS
#3 DR-DOS
#4 OpenBSD
#5 Solaris
#6 Darwin
#7 BeOS (Even if the company is gone, you can still get the install CD)
#8 FreeDOS
#9 VT-OS (If they design a TCP/IP stack for it?)
#10 [link|http://www.freedows.org|Freedows] (If Gateway contributes to it and gets it out of "vaporware" status)