I'm still hoping they retain some 4-core, low-end model. I doubt it, but I really can't justify getting an 8-core Mac when I'd be happy with 2 cores and a few desktop niceties. If they update the MBP, that might become a more reasonable option even though I swore my next computer would be a desktop.
A base MacPro (minus monitor) costs as much as the 15" 2.4 C2D MBP. If the entry level 8-core penryn comes in at the same price you might as well get that. Even though 8 cores may be overkill now, your computer will last much longer without upgrading. Plus, while programs like photoshop don't currently utilize 4-core processors, it won't be too long before they do, causing a nice speed increase.