Leo:
to slobber over so./sth.- gefühlsduselig von jmdm./etw. schwärmen
to slobber over so./sth.- von jmdm./etw. schwärmen

a) jmdn. schwärmerisch verehren; etw. sehr gern mögen: für große Hüte, schnelle Autos s.; in ihrer Jugend hat sie für meinen Bruder, für Beatmusik geschwärmt
b) von jmdm., etw. begeistert reden: von dem Essen, dem Konzert, der Frau schwärmt er heute noch
© 2000 Dudenverlag

Younger cinemagoers found it repulsive to watch Allen - in his sixties - slobbering over the likes of Julia Roberts

All this is given two hours of screen time, and is weakened by some obvious slobbering over the bucolic surroundings.http://www.thisislondon.co.uk/film/review-233...

The English dictionary entries on this are not that helpful, but here is one entry that shows why these don't fit:

slobber over something/somebody
phrasal verb
to show how much you want, like, or love someone or something, without controlling yourself:
[British English] I caught Rick slobbering over the models in a magazine.http://www.ldoceonline.com/dictionary/slobber

When you slobber over something, the thing you are slobbering over must be in front of you (or a picture of it), and you can easily be alone. When you von etwas schwärmen, the object of your admiration does not have to be there, but you can't be alone, as von etwas schwärmen means you are telling someone how much you like a thing or other person.

Slobbering over sth. is like drooling over something, but less attractive. It doesn't mean you are telling anyone anything. The figurative meaning is the same: you are excessively excited about something, not telling someone how excited you are.

For the example "slobbering over the bucolic surroundings", "für etwas schwärmen" might work - though "slobbering" is unattractive, usually a negative thing, whereas "schwärmen" is more positive, isn't it?

For the "slobbering over Julia Roberts" I would have suggested "ansabbern", but the word isn't in any of my dictionaries.