10. A speech processing method, comprising: determining a variable set of available commands; determining command structures corresponding to the determined set of available commands; processing a natural language speech input representing at least one command with respect to the determined command structures, with at least one automated processor, wherein an interpretation of the natural language speech input is dependent on the determined variable set of available commands; determining and preserving in a system state of the at least one automated processor prior to the natural language speech input; determining if the natural language speech input likely represents a command; determining a completeness and an ambiguity of the represented command with respect to the determined command structures, and if the likely at least one command is too ambiguous or incomplete for execution, obtaining further speech input to reduce ambiguity or incompleteness, wherein at least said obtaining is adapted to change the determined system state, such that a system state before said obtaining further speech input differs from the system state after said obtaining further speech input; executing the represented command with at least one automated processor; and reverting the at least one automated processor to the determined preserved system state with further changes in the system state resulting from executing the represented command by the at least one automated processor.
10. A speech processing method, comprising: determining a variable set of available commands; determining command structures corresponding to the determined set of available commands; processing a natural language speech input representing at least one command with respect to the determined command structures, with at least one automated processor, wherein an interpretation of the natural language speech input is dependent on the determined variable set of available commands; determining and preserving in a system state of the at least one automated processor prior to the natural language speech input; determining if the natural language speech input likely represents a command; determining a completeness and an ambiguity of the represented command with respect to the determined command structures, and if the likely at least one command is too ambiguous or incomplete for execution, obtaining further speech input to reduce ambiguity or incompleteness, wherein at least said obtaining is adapted to change the determined system state, such that a system state before said obtaining further speech input differs from the system state after said obtaining further speech input; executing the represented command with at least one automated processor; and reverting the at least one automated processor to the determined preserved system state with further changes in the system state resulting from executing the represented command by the at least one automated processor. 12. The method according to claim 10 , further comprising maintaining at least one data structure representing at least a status of a grammar, wherein the data structure is updated based on the natural language speech input and a context; wherein the variable set of available commands is determined dynamically.