Absolutely. Personally, I think there is something mildly offensive about sending out a company-wide email announcing layoffs without bothering to capitalize your sentences. Apparently this is standard practice for Jerry Yang, though.

i think that the use of capital letters will decline while most of our writing is done on screen and the world becomes smaller still. most writing systems make no distinction between capital and lowercase letters. also, eventually the american spelling system will become dominant. jerry is probably incorporating the same philosophy that is highly regarded at apple, google and by many ui designers: "if it aint needed, get rid of it"