Chen and myself got a question during our LWUIT session in J1 which in retrospect we probably didn't answer correctly. Text input in LWUIT today goes to the system native text box and returns when the user approves the change to the text.
One of our biggest users asked us in the past for a "lightweight" text widget, this would allow fast input for numbers or search fields but won't support predicitive text (T9). Such a future development won't replace the option to go to the native text box but would supplant it mostly for the simpler input types (e.g. numbers) and for input types where T9 is less important (e.g. search where mostly names are typed).
So when we got a question of how input is implemented in LWUIT we made the mistake of discussing the future support for lightweight input rather than the already existing support for standard text box input.BTW for lightweight numeric input we already have a sample in the developer guide which implements a numeric text field with a blinking cursor so this should be a feasible component.