I previously speculated that the upgrade eligibility window for XE3 might have been edged open ever so slightly. Sadly it seems this is not the case (German language forum). At least, not unless they extend another upgrade offer as they did with XE2.
Here’s the response, as translated by Google:
If you are a D2009 licensee wishing to upgrade to XE3 but in no hurry to do so right now, you might want to clarify with Embarcadero how long you will be eligible to do so, in case they close the door before you get around to it.
Thanks to Sebastian for mentioning this in the comments on my previous post.