If you're heading to the conference and haven't yet booked your room, there's another way to save. One of the many deals the Westin is offering is a "rejuvenate" package.
Go directly to the Seattle Westin site, click Hotel Deals, and scroll down to the "Rejuvenate this winter and enjoy rates from $159" section. As of today, it's not quite "$159," but for me, it was $177.
Hotels are desperate for business. No one is traveling, especially business travelers.
To give you an example, I'm staying in Seattle for the rest of the week for a little vacation. using the information I can get from BiddingForTravel, I bid for a hotel at Priceline and got a winning bid of $41/night (for the Wednesday through Sunday) at the Hilton at the airport. For comparison purposes, going directly through the Hilton's website, the best rate they offer is $143/night.
To be fair, using this method for the conference days itself wouldn't guarantee that I'd stay at the Weston, which is why I've not done it. (For those who want to know, the Westin is one of the top winners of reported bids for 4* hotels in downtown Seattle over the past year, but so are the Edgewater (a good 8+ block walk) and the Hotel Vintage park (6+ blocks away).
But if you haven't booked your hotel yet, or are even on the fence about going, you can reduce yoru hotel costs if you work at it.
One additional tip: If you want to try and contact the Westin directly to negotiate, try and contact a local representative. The folks on the "standard" 800 reservation line are usually less able to offer any sort of accommodation on accomodations.