Hmm... what would I do. A bunch of things, actually. I can detail them:
Pricing: It's clear to me that many will see this as a WiiMote clone. So I need to make it cheaper, to get it into more peoples' hands. A Wiimote + Nunchuk retail for $59.98. (Most games do not need WM+, so I won't look at that cost.) So I'd bundle a move and subcontroller together for $54.99, also keeping it at the same price as the DS3 controller.
Next is the bundle. An Eye-toy can be had for $30 fairly easily. Add in a game for $5 more to drive home value (Hey, it worked for Wii Play), and make the starter set $89.99.
Then we have the system. I don't want to touch the $300 system, it's too razor-thin on the margin already, and giving up this price point is a bad idea. But the $350 system is getting killed. I see raising the price, to $379.99, and adding in the starter set. (This offers a $10 savings and a bigger hard drive, further driving value.)
Launch: When games are ready. The US launch of the Saturn shows what happens when you have no games at launch. Of course, I'd also not have the games rushed to meet a time window. If the games were ready, I'd want to do a July launch, to spark interest in what is typically the slowest time of the year for gaming. Barring that, I'd do an October launch, giving me ample time to restock stores from a (hopeful) launch sellout before everyone is trying to get them for the holiday season.
Advertising: This needs to be a 2-pronged approach. Split the budget into 2 parts, about 1/3 and 2/3. If I get my July date, advertise to my core audience with the 1/3 part. Show big games using Move, have a few Butler ads, etc. If I get my October date, then throw a casual ad or 2 in there, showing people having fun using Move. Then November comes, and this is where the other 2/3 comes in. A good chunk of this will be spent on "casual" ads, showing people together having fun, families if possible. Drive home the idea of a PS3 as something else to pull families closer; a good holiday gift for the household. But I'd still keep a few Butler ads running, even creating a new one to keep the attention of my core base, to keep them talking about PS3 for the holidays.
Of course, since I don't have all the internal information from Sony, this is only what I would like to do if it were my job to market. It makes sense to me...