yet? (I'm assuming it has been around a while since you mentioned the K-1 going out every year or two).
If you don't sell assets from the estate soon after death, it is very possible that the assets continue to appreciate, in which case, you would owe tax on the delta increase from the date of death to when you actually sell the properties. If a trust is involved, depending upon the type of trust, and if this was a married situation, where one is still alive, it could also affect what and how much is taxable.
Also, keep in mind that inherited IRAs/401ks will be taxable to the recipients.