[sokoloff]

When the RSUs vest, what typically happens is both of the things you describe. A number of shares is withheld at vesting and the value sent to the Treasury as an income tax withholding. The following April, you true-up the full tax liability with the full number of shares treated as ordinary income. (The withholding is typically at the supplemental wage rate [22%, used to be 25%], which is frequently not enough to cover the full amount of tax due.)

Your initial comment suggested that you didn't distinguish between the ordinary income and capital gains taxation for the pre and post time periods. It turns out you did understand that distinction, but I didn't glean that from your prior text.