Yes, it would, I don't know if it is in, though ... I'll try to check over the weekend. Best of both worlds - in general PL/Tcl kind of sucks for doing queries because you have to do any query caching yourself since it uses the SPI interface.
PL/pgSQL hasn't allowed dynamic SQL because it is a compiled language (into bytecode+query plans). Having a dynamic EXECUTE (which undoubtably uses the same SPI interface as used in PL/Tcl and referential integrity checking, etc) would be a great improvement.