createdigitalmusic posted some hacking tips, including information on how to build your own MIDI clocking and how to create a "switchonome". Another post by runagate describes how to Turn A $50 Bliptronic 5000 Into A Monome Controller [update: Bliptronome conversion kit for $68 USD].

Information via ThinkGeek:

Product Features

* Unusual retro synthesizer is played with a grid of glowing buttons
* Create looping patterns and change them dynamically while playing
* Chain multiple units together and create more complex melodies
* One octave range. 8 notes can be played simultaneously
* 8 different old-skool synth sounding instruments to choose from
* Sounds created using FM waveform synthesis
* Set the BPM (beats per minute) from 60 to 180 in 20 BPM increments
* Built in speaker with headphone jack and line-out jack
* Front panel is constructed from brushed aluminum
* Includes, manual and 2 link cables for connecting additional Bliptronic units
* Requires 4 x AA batteries (not included)

What is a monome? "a reconfigurable grid of backlit keypads which connects to a computer. interaction between the keys and lights is determined by the application running on the computer. there is no hard-wired functionality."

(see more videos of the monome on vimeo)

A Monome for the rest of us. The new Ableton Live Controller by Novation looks quite like the monome. Still, if it integrates in Ableton as well as the Akai APC 40, it can be a quite handy - and cheap: 150€ (199US$) is said to be the street price (to be released Nov '09).

Still since the APC40 uses a proprietary protocol, it is uncertain if the Launchpad will be usable for controlling other things than Ableton Live.

Here is the full Press Release Information from Ableton AG:

Ableton is very happy to announce Launchpad, a new dedicated controller for Ableton Live, co-developed by Novation and Ableton.
Launchpad features a multicolor, 64-button grid for launching clips, as well as dedicated scene-launch buttons. Despite the big grid, Launchpad is compact and portable: it'll fit in your bag for gigs and won't hog your desk space in the studio.
Launchpad doesn't just launch clips. In mixer mode the button grid offers a unique way to control Ableton Live's mixer. Two fully customizable user modes transform the grid into a drum pad controller, a DJ effect controller or anything else you can think of. These user modes make Launchpad the ideal hardware counterpart for Max for Live (coming soon).
Launchpad is Automap-enabled, and if 64 buttons aren't enough, you can link up to six Launchpads together.
Launchpad comes with a special Live 8 Launchpad Edition and 1GB of sound content. Launchpad will be on sale worldwide starting on November 1, 2009. Pricing is expected to be around USD 199 (MAP)/149 EUR (VAT not included).

Weitere Informationen, Videos und genaue Spezifikationen finden Sie auf:
http://www.ableton.com/nl398-launchpad

[Update 12/2011] Das Novation Launchpad ist aktuell ab 153€ erhältlich.

three models: two fifty six (16×16), one twenty eight (16×8), and sixty four (8×8). each is a reconfigurable grid of backlit keypads which connects to a computer. interaction between the keys and lights is determined by the application running on the computer. there is no hard-wired functionality.

I am really looking forward to get one od those. If anyone wants to sell his 8x8 version, please drop me a mail. Currently only the DIY-Kits of the 40h version are available again, everything else is sold out. I think i will get myself one, stay tuned for a detailed review when i got it.