I wouldn't make that assumption. Apple hasn't announced anything yet and the MBP just had a major refresh in January. The new Intel chipset has been delayed, which will likely further push back any product updates.
Buy the machine you need now and it will continue to serve those needs long after an updated model is released.
Yeah, that is true. If I get the MBP now, I will definitely be happy with it even if there is an updated version coming out soon. I'll give it a few more weeks to hear more news though. Can't really hurt I guess, since my PBG4 still runs very well.