Looking at the results so far in primaries only (not including caucases) Sen. Clinton has done better than Sen. Obama in CLOSED or MODIFIED democratic primaries.  Sen. Obama has done well in Open primaries for obvious reason (independents).  Here are the results so far:
Closed/Modified primaries:
Sen. Clinton wins: New Hampshire, Florida, Arizona, California, New Mexico, New York, New Jersey, Massachusetts and Oklahoma. (9 wins)
Sen. Obama wins: Washington DC, Maryland, Louisiana, Utah, Connecticut, and Delaware (6 wins)
(Washington DC, Maryland and Louisiana with large African American voters benefited Sen. Obama).

Open primaries:
Sen. Clinton wins: Michigan, Tennessee and Arkansas (3 wins)
(Michigan was not contested and Sen. Clinton benefited in Arkansas from her past ties)
Sen. Obama wins: Wisconsin, Virginia, Missouri, Illinois, Georgia, Alabama, and South Carolina (7 wins)
So majority of Sen. Clinton's wins come from Closed/modified primary states.  Sen. Obama has done better in Open primary states.

What does it mean going forward? Here are the primaries going forward.
Date    State             Type        Delegates    Advantage
4-Mar    Ohio            Modified    161    Clinton
4-Mar    Rhode Island    Modified     32    Clinton
22-Apr    Pennsylvania    CLOSED            188    Clinton
6-May    Indiana            Modified     84    Clinton
6-May    North Carolina    Modified    134    Clinton
13-May    West Viriginia    Modified     39    Clinton
20-May    Kentucky    CLOSED             60    Clinton
20-May    Oregon            CLOSED             65    Clinton
2-Jun    South Dakota    CLOSED             23    Clinton
7-Jun    Puerto Rico    CLOSED              55    Clinton
Total delegate Advantage Clinton    841     

4-Mar    Vermont            OPEN             23    Obama
4-Mar    Texas            OPEN            228    Obama
11-Mar    Mississippi    OPEN             40    Obama
3-Jun    Montana            OPEN             24    Obama
Total delegate Advantage Obama            315     

The data shows that going forward Sen. Clinton has advantage over Sen. Obama if the pattern of winning in Closed/Modified primaries holds for Sen. Clinton.  As there are only 4 open primaries left. Also, if Sen. Clinton can score a victory in Texas then she will have a significant advantage with the total wins and delegates.  Time will tell.