Both wheels are secured, which is good, but "inexpensive" and "cable" don't inspire much confidence. There's no such thing as a fool-proof bike lock, so what you should try to do is to make it as time-consuming as possible for any potential bike thief.

You have to take into considerations the risks of the area. Like ItsJustMe says above, if this is good enough for your area, then fine. If it isn't, then either get a U-lock as well and use the two in combination, or park next to a bike that's less secure than yours is, and/or a more attractive bike for a thief. You've got an attractive bike already, so chances are your bike is going to catch a potential thief's eye more than most other bikes.

My judgement: you could be doing a lot better. Invest in a U-lock, use the U-lock to secure the rear wheel and frame to the bike rack, use the cable to secure the front wheel to the U-lock. This video should give you a good idea of what's a good locking technique:

http://www.streetfilms.org/hal-grade...-bike-locking/