A lot of vendors have been bandying around dates in the middle of this year, for the arrival of 802.11n, the fast Wi-Fi standard. They may be being deliberately imprecise.
Now "arrival" of a standard can be a vague term, since it may be possible (or even necessary) to get products out, before all the i's are dotted. 802.11n is definitely an example of this, with the Wi-Fi alliance already certifying products that are designed to meet a standard that, if we're being precise, won't be finalised till June 2009.
The current IEEE timeline expects the standard to be approved by the 802.11n working group in March 2009, and fomally approved by the IEEE standards board in June 2009, after which time it becomes an official standard.
I don't think there's ever been any serious change between the WG approval and the final standards board approval, and standards also change very little in the last stages of the working group process.
This year's 802.11n products apparently work - though their interoperability, performance, and power demands and so on will be tweaked as the year goes on.
But if anyone says they're waiting for the final, official 802.11n standard, they mean 2009.