I've tested this using both a galaxy S2 and S3. On the S2 the above page is safe and triggers the exploit to view the IMEI. On the S3 it launches the dialler however, the dialler is empty and does not display the IMEI.
After investigating further, the S3 does not launch codes that begin with * # but will trigger the factory reset code which is in the format of * 1234 * 1234 #
Edit: Those with an S3 can confirm this by visiting http://no.tl/s.html in which I've embedded * 1234 * 1234 # (which is not the reset code, but is the same format)