New bike - high idle

This is my first post here.

I recently bought my first bike, a Suzuki Katana 600. The other day, it was a bit cold out (40 degrees), so I started my bike with the choke all the way open and ran back into the garage to grab something, thinking that I would have 20 seconds or so to get back before the engine warmed up. Turns out it starts revving high sooner than I thought and so I ran back to close the choke.

So, my big question is if those 10 seconds of high idle would have damaged anything. I'm guessing it was about 5,000 RPMs, and the exhaust was a little smokey. I rode it right afterwards, and it seemed fine.

Should I worry?    

You shouldn't have any problems. The exhaust was smokey due to a combination of the cold engine and rich mixture.  

I had a 99'YZF R6 (it was the bike of the year then) and it was carb'd. I would start it every morning with the choke on and rev's high. It was fine. Once my cluster read a temp (107 or so) I turned of the choke and at times, I would chill for a few minutes. I had to finish my smoke and put the rest of my gear on, right? Make sure you keep up with your maintanence, tire pressure, etc. Stay shiny side up!  

Your Choke, if set correctly, should not take the RPM beyond the Safe Cold Start RPM Limit.  If you have a Service Manual for the Bike, it should have this value stated.
As a general 'rule of thumb', the RPM on a Cold Engine sould not be allowed to exceed 2500, as it will take a few moments to expand with the heat, settle into its Bearings, and allow for the Piston Rings to Seat.  Some Bikes do have a higher threshold that they can withstand, but you really should find what your Choke should be set for at Wide Open.
As for damage, it would take more than 10-30 Seconds to do any severe damage.  Prolonged high RPM (5 mins. or more) , or repeated use of high RPM to warm it, will undoubtedly shorten the engine's life span.
More important, Never Start Your Bike, and Walk Away!!!  There are a range of nightmare issues that can result, of which Idle Wild is low on the list!!!
Ride Safe!