"Here I Come" is a song by pop singer Fergie featuring will.i.am, produced by will.i.am for her first solo album The Dutchess (2006). It was used on the commercials that advertised the debut of the new channel CW and in a Motorola Rockr commercial for Latin America and Portugal featuring Fergie. The song of the debut network of 2006 following the closure of UPN and The WB.
Although not released as an official single in the U.S., it has been used on numerous advertisements and television shows,[citation needed] including a season one episode of Ugly Betty. Notably, a sample of the song with slightly altered lyrics is used in a campaign promoting the recently created CW Television Network. It was released as the album's sixth single in Australia, New Zealand and Brazil. It was the second most added song to Australian radio, in its first week of release.[2][not in citation given] A sample of The Temptations' song "Get Ready" is heard on the track. The song was also used in the Motorola advertisement which also featured Fergie. The song was also featured on season 3 of So You Think You Can Dance, where Kameron Bink and Lacey Schwimmer danced a hip-hop routine to the song, choreographed by Dan Karaty. The songs was also featured in the trailer for the 2008 comedy film Confessions of a Shopaholic starring Isla Fisher.
http://en.wikipedia.org/wiki/Here_I_Come_(Fergie_song)

If you google "Here I come" you will find the phrase in a number of songs/expressions. Here it probably means they would gladly have a job like that.

this phrase is just a way of saying that the woman in question is wealthy enough to shop at the French jewellers VC&A whenever she wants

http://en.wikipedia.org/wiki/Van_Cleef_&_Arpels

I might be wrong but I don't think 'Here I come' relates to any particular film.

--------------------------------------------------
Note added at 8 mins (2010-09-13 12:38:57 GMT)
--------------------------------------------------

There is a play and film "Philadelphia Here I come" but I wouldn't know which come first - the play title or the expression in popular language

http://en.wikipedia.org/wiki/Philadelphia_Here_I_Come!
http://www.imdb.com/title/tt0284690/

"here I come," is an English language phrase which calls up the image of something like, be ready, I am coming or look out ! I am on my way !

HERE IS AN OLDER POETIC EXAMPLE:

THE VOICE OF THE GRASS
Sarah Roberts Boyle [1812-1869]

Here I come creeping, creeping everywhere, by the dusty roadside, on the sunny hillside, close by the noisy brook, in every shady nook, I come creeping, creeping everywhere. Here I come creeping, creeping everywhere, all around the open door where sit the aged poor, here where the children play in the bright merry May I come creeping, creeping everywhere.

Here I come creeping, creeping everywhere. In the noisy city street my pleasant face you'll meet, cheering the sick at heart, toiling his busy part, silently creeping, creeping everywhere. Here I come creeping, creeping everywhere. You cannot see me coming; you hear my low sweet humming, for in the starry night and the glad morning light, I come creeping, creeping everywhere. . . .

Here I come creeping, creeping everywhere. When you're numbered with the dead in your still and narrow bed, in the happy spring I'll come and deck your silent home, creeping silently, creeping everywhere.
http://womenshistory.about.com/library/etext/poem1/blp_boyle...

--------------------------------------------------
Note added at 31 mins (2010-09-13 13:01:43 GMT)
--------------------------------------------------

HERE ARE SOME MORE MODERN EXAMPLES:

Look Out Kindergarten, Here I Come! – by Nancy Carlson
http://booksellers.penguin.com/static/pdf/b2b-look-out-kinde...

Look out world, here I come!: a Ziggy collection of down-to-earth humor By Tom Wilson

A few months ago, I was sent Look Out World, Here I Come: New York Adventure Kit for my 5 year old daughter. It wasn’t until just a few weeks that we actually took a look at it and I’m so upset that we didn’t see it sooner. Living in New York has made us appreciate the city even more now.
http://newyorkchica.com/2010/07/look-out-world-here-i-come-n...

From the context, it sounds like a woman has a job that provides her with a huge/unlimited income. Either she (or someone else who is benefiting from this arrangement) is excited about the large amount of money because it will allow her to shop at expensive places like Van Cleef & Arpels. When she says, "Here I come," she is "speaking" to the store...saying: Get ready for me! I am going to be a regular customer there!!

There is an implication in the phrase that the person is new to this sort of wealth, and that this type of unrestrained spending will be a new experience for her.

Another example would be of someone raised in a small town who takes his first trip to New York. "Speaking" to the city before his trip, he might say, "Big Apple, here I come!"

It means something like: New York, you have never seen anything like me before! Get ready for my arrival!!

I don't believe this phrase is necessarily tied to any specific film or song as suggested by the other entries. Even if it is, the information is not needed to understand the phrase, which is a common one in the U.S.

It should be set in the text as somebody's remark.She is in a position to dictate her will, as she is more independent (from now on-?). Supposedly, they are watching her as she enters the shop/cafe.