The Simulator for Arduino has just been upgraded. There are many fixes and while there still some issues such as being able to process one expression over 10 lines, overall the Simulator does well. Lately there have been many error reports about floating point numbers, and this is due to Windows assigning a comma to the decimal symbol - see here
One of the best improvements is the support for LCD which allows any size (within reason) and colour of character LCD screen (using the Liquid Crystal library) to be simulated. The video is coming soon.
Download from here
Webhelp is available from http://arduino.com.au/help/
Oh, and the Free version now has a 14 day period or 100 sketch limit before the 30 second timer kicks in. The days left and sketches left is shown in the status bar on startup.
For the Pro Licence, the price is $12 but there are some coupon discounts (25 coupons in total) if SIM1K is entered on checkout.
Also, a new iOS app Arduino Circuits Simulator was released on 10-Nov but it couldn't even compile int i=2; This app is by Schogini who make other the iOS app which has received 6 one-star reviews, so buyer beware for iPhone Arduino Simulator apps!