One of the reasons why I felt the Xperia X1 was unpolished was that many of the panels still defaulted to Pocket IE, when, in an apparent last minute decision, the excellent Opera Mobile 9.5 browser has been included.
Apparently the shipping hardware does not fix this issue, but fortunately fixing this yourself is not too much of a struggle. To change the Google panel to default to Opera Mobile one simply need to edit the xml fine found at \Program\Panels\GooglePanel replace all instances of iexplorer.exe with operaL.exe.
Of course many of us are not down with editing xml files, so xda-developers member [email protected] has simplified the process by making the edited xml file available, which simply needs to be copied over the one in the GooglePanel directory.
Download the xml file form this xda-developer post here.