Oxygen is indeed important to yeast metabolism, and having some oxygen in solution at the start of fermentation is beneficial. I am one of those who does the whole oxygen/diffusion wand thing at the start of fermentation, and I did notice improvement in my overall fermentation after starting to use it. After reading the book Yeast, I was convinced that simply agitating/swirling/sloshing or other mechanical means just didn't get the adequate amounts of oxygen needed.
Packaged: Pearl Amarillo SMaSH, A bunch of random stuff...
Recent Meads: Mead Day '11 Ginger Metheglin, Mead Day '12 Traditional (orange blossom) Mead, Fresh Simple Cyser '12
Primary: Graff, Simple Cyser, Basic Spiced Cider
Secondary: Why do I keep this line here...?
Bulk Aging: Cocobochet
Planned: Heady Topper Clone! Wild Cider?, Hop Metheglin #3 (NZ hops), Trad. Gesho T'ej