Subject to the terms and conditions of this Agreement, Licensor hereby grants, in exchange for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, to Digia a sublicensable, irrevocable, perpetual, worldwide, non-exclusive, royalty-free and fully paid-up copyright and trade secret license to reproduce, adapt, translate, modify, and prepare derivative works of, publicly display, publicly perform, sublicense, make available and distribute Licensor Contribution(s) and any derivative works thereof under license terms of Digia’s choosing including any Open Source Software license.
One difference is that the Qt source code is also covered by the KDE Free Qt agreement (linked in a sibling comment), which basically acts as a poison pill to ensure that no future owner of Qt can pull an Oracle and close off development.
For this reason, it's my opinion that the Qt CLA is much, much, less onerous than other CLAs, like Google's or Canonical's, in the sense of how much control is actually given away.
