ANSWER
From left to right:
(Jesus Christ)
Speedy - Alka-Seltzer
The Michelin Man (aka Bibendum) - Michelin Tires
Elsie the Cow - Borden
Reddy Kilowatt - your local electric company
Big Boy - Big Boy Restaurants
Nipper - RCA (US), HMV (UK), and JVC (Japan)
Speedee - McDonald's
Speedy (dead) - Speedy was last seen in the 1980's, in a joint commercial for Alka-Seltzer and H&R Block, making the logical link between income taxes and heartburn. He was also involved in the "Save Big Boy" campaign in the mid-eighties.
The Michelin Man (alive) - The Michelin Man got the name Bibendum from an early ad which featured the Latin phrase "Nunc est bibendum", which means "It's time to drink". The ad depicted the Michelin Man drinking a glass filled with nails and broken glass. The Michelin Man still appears in television commercials today.
Elsie the Cow (life support) - Elsie the Cow still appears on milk products from a regional producer in Texas and Louisiana. Elsie also appears on cheese products marketed by the Dairy Farmers of America cooperative.
Reddy Kilowatt (missing, presumed dead) - Reddy Kilowatt was created in the 1920's at the Alabama Power Company, and over the years was licensed to hundreds of different local and regional power companies. In 1998 he came to be owned by Northern States Power Company. Shortly after they merged with another company to form Xcel Energy, Reddy disappeared from public view. Foul play is suspected.
Big Boy (critical condition) - Bob's was the first of the Big Boy restaurants, but the concept was franchised across the US under a variety of names, including Elias Brothers, JB's, Frisch's, and Shoney's. Today a small number of Big Boy restaurants still exist in California and a handful of other states.
Nipper (alive) - Nipper, who still appears around the world today, is probably the oldest mascot in the list (unless you count Jesus Christ). He was an actual dog who really cocked his head quizzically when hearing a gramophone. Francis Barraud completed the now famous painting of Nipper in 1899, seven years after Nipper passed away. That same year he sold the painting and its copyright to the Gramophone Company (UK). The Berliner Gramophone Company (US) acquired the US rights to the trademark a year later.
The Nipper mascot descended over the years to a number of successor companies, including the His Master's Voice record label, which today survives as music retailer HMV, a subsidiary of EMI; the Victor Talking Machine Company, which merged with RCA, and which after passing though the bowels of GE, is today owned by Thomson Electronics (RCA consumer electronics), and Bertelsmann AG's BMG division (RCA record label); and JVC, which began life as the Japan Victor Company, a subsidiary of RCA-Victor.
Speedee (retired) - Speedee was replaced in the early 1960's by a clown, and has not been seen in advertising since. The Speedee mascot can still be seen at the world's oldest operating McDonald's restaurant in Downey, Califonia.
WHO GOT IT RIGHT: Bob Milligan, JP Weigt, Christine Severen, and Marc Quinlivan.