does my wife have to pay taxes on my Life Insurance?
Generally speaking, if you controlled the policy (e.g. were the one authorized to make changes to it), no. But, it would likely count against your estate and thus your estate would essentially have to pay taxes on it if your total estate value was above the exemption amount. Currently, the federal exemption is $5 million and the rate is 35% above that. That exemption could, of course, change though.
Also, who knows what crazy scheme Maryland will come up with. For a period of time, it had put in place a ridiculous scheme with regard to taxing estates. It had traditionally had a fairly low estate tax rate (i.e. compared to the large federal rate). But, after the federal laws were changed, early in President Bush II's Administration, to increase the federal exemption above $1 million, Maryland designed a system where its own rate remained fairly low up to a certain amount of the estate, and then spiked to a very high rate for a small range of the value of the estate (I don't recall the range, but it would have been something like between $1 million and $1.4 million), and then dropped back down to a low rate above that range. In effect, what Maryland was doing was claiming for itself the federal estate tax which was then not going to be paid to the federal government because the federal government decided to raise its exemption. It essentially said -
'well, since the feds don't want that tax revenue, we'll just take it ourselves.'
The last time I looked at Maryland's tax laws, it appeared to me that that scheme had been changed back to something more reasonable (and less offensive). But, as I said, who knows what it will do now that the federal government has enacted a $5 million exemption going forward. If it did something similar, life insurance policies that pushed the value of an estate over $1 million or $2 million might end up being heavily taxed by the state.
EDIT: Since the OP's question was about life insurance going to a spouse, rather than life insurance going to someone other than a spouse, and since federal estate tax law allows much of the property that goes from a decedent to a spouse to be deducted from the decedent's gross estate for estate tax purposes, I decided to do a little research with regard to the estate tax treatment of life insurance proceeds paid to a spouse. In short, I'm still not sure if such proceeds are covered by 26 U.S.C. § 2056, and thus not taxable for the estate. But, I suspect that they are, which would mean there would be no (estate) tax on them.