Having unfortunately missed this year's Consumer Electronics Show, we've been wondering what other conferences and trade shows exist that might include 3D printing content. Searches reveal what we think might be a fairly comprehensive list of major events involving 3D printing. We've not included numerous local events such as local Maker Faires.
CES, January 10-13 in Las Vegas
RapidPro January 25-26 in Veldhoven, Netherlands
SolidWorks World February 12-15 in San Diego
AMUG (Additive Manufacturing User Group) April 22-26 in Costa Mesa California
Maker Faire Bay Area May 19-20 (Tentative) in San Mateo (Other Maker Faires will likely be held in Detroit and New York City later in the year)
Rapid May 22-25 in Atlanta
Plastics Design & Moulding Exhibition & Conference May 29-30 in London
SigGraph 2012 August 5-9 in Los Angeles
TCTLive September 25-28 in Birmingham UK
EuroMold November 27-30 in Frankfurt
These events tend to occur annually, thus this list is probably the set of 3D printing conferences you should always watch for product announcements.