Considering that the MacBook line was just updated to Santa Rosa Nov 1st, I doubt that there will be any major updates to the current form-factor MacBook in the next few months.
All the rumors are hinting at a ultra-portable MacBook Pro, or some sort of tablet device. Neither of these sound like what you are looking for if a current MacBook is what you are considering. And, like cwa107 says, rumors are just that, rumors.
Before purchasing my MacBook, I waited for the C2D over the CD, but that was because I didn't have an immediate need for the new laptop. Since January when I bought it, there have been two updates to the MacBook, but neither of those make my laptop any less powerful or less useful than when I bought it. You really don't want to fall into the trap of always wanting the "latest and greatest" as you will either never get anything, or never be satisfied.
If the current spec MacBook meets your needs, then get it and don't look back.