If Apple stays true to cyclical form, they will announce multiple new machines within the next 2 to 3 months.

All their desktops are due for a refresh as are their displays. I'd expect them all to be refreshed by WWDC time.

Apart from refreshes, there are also the rumors of new form factors. I won't hold my breath for anything on that front, but you never really know what Apple has down the pipe (even when you're "IN the know" you rarely know )