Nothing new, every politician has done the same thing or something simular. If you don't fight the people set to destroy you, who will? FOX and other right wing media outlets seem to be set more on discrediting Obama instead of reporting all the facts. The same can be said for the left wing media outlts. So why not investigate the people dead set on destroying you.
Also, I find this to be pure sensationalism not journalism. To compare the use of private investigators under two different administrations is one thing, but to try to show a link to watergate is ridiculous. Nixon did othing wrong by hiring private investigators. The private investigation were not wrong or illegal. Incase you missed it Nixon resigned because:
Taken from the article you provideed
The Nixon White House, in the vernacular of the day, "stonewalled." Once they did all these things they made false statements to investigators, withheld evidence, counseled witnesses to lie, interfered with a Justice Department investigation… and that's only a partial list of Article I of the three Articles of Impeachment drawn up by the House Judiciary Committee that, along with the release of Nixon's tapes, forced his resignation.
When Obama does those things, he will be impeached and then a comparison to Watergate can be made.