@Rob Apparently, you still don't get it. There is no specified time period for a Default judgment to be set aside. Hyperion could at any time file a motion to request this, and it will be up to the judge to determine if there is "Good Cause" to do so. But this discussion is really pointless.
Since, you have not been following this case you simply don't realize how very obvious it is, that Hyperion never intended to respond to this case.
Now exactly why is not known, but it's likely that Hyperion expects this judgment to be unenforceable outside the U.S. and what was at stake in the U.S. simply was not worth the legal cost to defend. Also, unlike the rather dubious definition of OS4 in the settlement agreement (which Hyperion used to claim rights to any version of Amiga OS) the Hyperion trademarks were exact and specific. So, Hyperion now has a much more serious problem claiming the rights to any trademarks they want.