This Sony VPL-HW50ES is fairly typical in brightness when compared to most other home theater projectors in its price range. Over the years, most of the over $2500, but under $10,000 projectors we've measured, have had "best mode" brightness in the 500 to 700 lumen range, and "brightest" is typically between 800 and 1100 lumens.
Thanks to 3D, we're seeing a number of projectors sporting extra 2D lumens these days. This is particulary true of the HW50 projector.
While it's still not a "light cannon" if you need tons of lumens and can sacrifice some color accuracy (a "brightest" mode), this Sony, calibrated is a good deal brighter than most home theater projectors. That makes it ideal for rooms with good light control, such as theaters, caves, and many media rooms.
Those numbers are all "right out of the box", without any adjustments. The two key brightest modes, Bright Cinema and Bright TV both topped 1100 lumens. That's still brighter than your average home theater projector in "brightest mode".
1281 lumens represents the highest that Mike measured (Game mode), and that with the zoom at mid-point. Not your first choice in modes, you'll probably stick with the almost as bright calibrated mode, or the Bright TV or Bright Cinema.