I hate to be a stickler for details (well it never stopped me before...

)
The 1958 date was ONLY the 50th anniversary of the introduction of the tube bottom brick... nothing more...
LEGO dates are so muddled (the official TLG site timeline mixes "first sales date" with "sales office opens date") that besides principle LEGO owner Kjeld Kirk Kristiansen, I doubt that more than a few old timers at TLG really know the true LEGO dates.
But here they are....
LEGO sets (Automatic Binding Bricks) were first produced in 1949 (63 years ago) in Denmark.
LEGO sets were first sold from 1950-51 in Sweden for a short time (poor sales) and then reintroduced in 1955.
LEGO sets were first sold in Norway in 1953.
LEGO sets were first sold in Germany in 1956.
LEGO sets were first sold in Switzerland, Netherlands, Belgium, Austria, Portugal in 1957.
LEGO sets were first sold in Italy in 1958.
LEGO applied for their tube bottom patent in 1958 (Patent Pending)... and started using the tube bottom bricks that year.... hence the 2008 anniversary date...
LEGO sets were first sold in France and Finland in 1959.
LEGO sets were first sold in the UK/Ireland in 1960 and Australia in 1962 via a license to Courtauld's Corp. (a chemical corp.)
LEGO sets were licensed to Samsonite of USA/Canada in 1961... the first sets were produced from a Stratford Ontario plant and shipped to the USA from 1961-65. Canada sales started in 1962 from that same plant. TLG said that USA Samsonite was under-performing, and litigated to get the license back from Samsonite in 1972. So TLG LEGO sales started in 1973... and in 1998 there was the USA Silver Anniversary (25 years) bucket (only going back to the 1973 date, and ignoring the 1961-72 Samsonite years). Since Samsonite of Canada "toe'ed" the TLG line better, their license was not revoked... so Canada anniversary for LEGO uses the 1962 date... which explains their 35th anniversary bucket in the late 1990s.
All this is explained (country by country) in Chapter 73 (LEGO Sales/History by Country) of my Unofficial LEGO Sets/Parts Collectors Guide (2,800 pages on DVD or as a download).
Edited by LEGO Historian, 03 July 2012 - 09:15 PM.