Specifically: Codeblocks is written using the GNU GPL license, but the programs you make with it, are NOT. wxWidgets DLL is distributied using the wxWidgets license, which states you can distribute the DLL in your commercial apps without requiring the distribution of the source code. So, yes, it's ok.
About making commercial grade applications, wxWidgets has been used to make applications like Shareaza, a very good file sharing program. In the wxWidgets site there are listed other applications built with it.
Remember, codeblocks is an IDE. What you do with the programs you buld with it, is your own business.