"Kür" and "küren" are remotely related to the "cern" part of the English "discern".

I'm sure I could find at least ten sports with a Kür-part (what is the English word fore "Kunstradfahren"? Figure cycling?). The verb "küren" is not obsolete. Just the range of contexts in which it can be used without eliciting laughter is smaller.

It remains today a (the most?) frequent choice of journalists to describe who is the winner of a beauty pageant:

"...wurde zur Schönheitskönigin Schwabens gekürt"

Another context in which this verb is often used is the "word of the year".

Fanmeile" wurde zum Wort des Jahres 2006 gekürt"

Some more uses from a random Google search:

"Küren Sie die besten Airlines" (Capital)
"Bester Deutsche Jungbrauer gekürt"
"Nicolas Sarkozy zum Präsidentschaftskandidaten der UMP gekürt ..."
or in Denglish:
"User küren beste Website"

Wolfgang