Upgrading from 10.2g to 11g by incrementals
Once you upgrade the destination database to 11.2, you won't be able to apply archived logs (or incremental backups) from a 10.2 database.  So no, this won't work.

It is, on the other hand, often possible to use an actual standby database to perform a rolling upgrade.  You can create the 11.2 database as a logical standby of the 10.2 database, let the SQL apply process keep the databases in sync, and then switch over to the 11.2 database when you are ready to migrate.  In a similar vein, you could also use Streams between the 10.2 database and the 11.2 database to keep the data synchronized and then switch over when you're ready to migrate.