Blizzard can tell if you have a third party program reading the active memory of the server.
The issue then becomes do they give a flying ****? The answer is no.
They are hard on afk-bot gold farmers, & since the Isle quests came about that issue has even stopped completely, plus they are gearing up for the launch of the lich king, honestly think they care about your level 70 gear when they know you will pay your script to fall over yourself to get more level 80 gear...
Just be cautious with the program, only run the bot 4-5 hours a day, switch up when you run it, say 3am - 8am one day then skip a day and 9pm - 12am etc, keep it random. Check in on your bot when you can... basically don't be an idiot with the program & your gonna be fine.