Although sampler and views_sparkline are
pretty close for D7 (if not already there) (As of 2012-11-04, sampler has a stable release and views_sparkline hasn't been started yet), the actual metrics in project_issue will need to be ported to D7. Basically, where all the data is coming from is different now. I think it's mostly just the classes in the project_issue/metrics directory that'll need to be touched -- the .inc files are probably all fine as-is.
This would be necessary if we want to keep displaying the sparklines in the "issues for X" block on project pages.