Unix Administrator and Linux Administrator transition

Hello Unix Experts,

I'm going to be graduating with a CIS (Computer Information Systems) degree in the coming year. I have been offered an internship with a job title of Unix Administrator under a well known company. I understand that Unix is used for high-end servers in many large corporations, but the market share is gradually declining to its competitor (Linux) (based on articles and statistics that I have read).

If in the next 5 to 10 years Linux becomes dominant over Unix would it be easy to transition from being a Unix Administrator to a Linux Administrator? I know that the underlying foundation of both OS's are the same, but would the differences be too overwhelming to make that transition? Any insight would be appreciated.

I'm no Unix expert, but I believe that since Linux aims to be POSIX compliant, the transition should be reletively painless.

brentmd, I can tell you this from personal experience.
I spent two years in school becoming a "UNIX System Admin"
Since finishing in 2002 I have yet to administer a "UNIX" box.
I can not tell you the difference between Solaris, HP-UX, or AIX.
All the machines "we" support run RedHat and the ones we don't
run Debian or CentOS.
From an admin stand point you shouldn't have any problems getting
around on a Linux box. And unless you are employed by an outfit that
deploys UNIX clusters you will most likely be working on more Linux
machines then UNIX. (Example: The datacenter at Texas Instruments
uses a UNIX cluster for very specific duties, but the rest of the servers
run Linux.)