Jon,
You probably know this but I'll post it for others.
That is exactly what I do when taking charts into PowerPoint and not
wanting to embed the entire workbook each time.
Actually, I create a copy which leaves the original chart in the
original workbook for the next update. I also copy the color palette
from the original workbook since I ofter use custom colors.

Also FYI, this chart inserted into PowerPoint is still linked to the
sourcedatarange and will automatically update to new data just by
activating the chart in Excel, but one wants to be careful about paths
here.

Brian Reilly, PowerPoint MVP