It appears that as of today, there isn't much concern about the phrase "as of."
Perhaps that's because it's such a simple phrase. Two words, two letters each, nothing flashy.
But this is That's What They Say, and when Michigan Radio's chief engineer Bob Skon asked us about the distinction between the phrases "as of today" and "as from today," we had to check it out.
The form "as of today" is seen as distinctly American. It shows up in the 18th century in formal dating. That is, when you're trying to suggest a date on which something starts. Around this same time, the competing form "as from" shows up, as in "as from today."
What we have here is an American/British distinction. "As of today" is more American, while "as from today" is British. It should be noted that British English is converging with American English on this point. "As of today" is now more common in both American and British English.
However, "as from today" does show up in American English from time to time. For example, Britney Spears uses it in this lyric from her song "Stronger": "I'm not your property as from today."
Regardless of which form you choose, "as of" can be confusing. A phrase like "as of Wednesday" has two potential meanings. It can mean either that something starts on Wednesday or that something ends on Wednesday.
Context helps though. For example, if someone says, "As of Wednesday, the new policy will be in effect," it's pretty safe to assume that the policy doesn't start until Wednesday. But if someone says, "As of Wednesday, we had sold 50 boxes of cookies," it sounds like it's possible more were sold, but the last time someone counted was on Wednesday.
Ambiguity aside, which do you prefer, "as of" or "as from"?