That is just fine for what is due tomorrow. And you are covered so far. [I hope you took into account what had been already withheld so far out of your paycheck]
But you can still go back and figure more precisely in future quarters and lower you payment if it looks like you are paying too much. There is no rule that says you can't change your method in later quarters based on income so far.
Audrey
Since I was maxing out a 401K in 6 months AND putting $ into a pre-tax medical fund AND my health insurance is pre-tax... I discovered I have only paid about $500 total in federal tax to date. Eeeek. I didn't even bother to deduct 1/4 of that. I just paid 25% of what I owed for 2009, wrote the checks, and cursed. The checks are in the mail.
I really appreciate all the help. I had just assumed that since I hadn't officially "planned" (announced) retirement, I could get around dealing with this until the Sept. payment was due. I decided it was more prudent (if financially painful) to pay quarterly for now. I'll have a good idea in January what happened - maybe even in September.
Thanks for mentioning I can amend it later if I'm paying too much. I am so not in favor of free loans to the IRS!
Thanks again for all the links, help, etc. In a year I can be the expert and help someone new, I hope!
Additional input is still welcome - this has been really helpful, probably not just to me.