大奥婚 is made of two words:

- 大奥 most likely refers to the movie [『大奥〜永遠〜［右衛門佐・綱吉篇］』](http://ja.wikipedia.org/wiki/%E5%A4%A7%E5%A5%A5%E3%80%9C%E6%B0%B8%E9%81%A0%E3%80%9C%EF%BC%BB%E5%8F%B3%E8%A1%9B%E9%96%80%E4%BD%90%E3%83%BB%E7%B6%B1%E5%90%89%E7%AF%87%EF%BC%BD).  As you can see from the Wikipedia link, both 堺雅人 and 菅野美穂 starred in this movie.
- 婚 is short for 結婚 ("wedding").

So you could translate it as "An Ōoku Wedding".

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In this question, you included a second (unrelated) question about 電撃.  The relevant sense in [大辞泉](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&stype=0&dtype=0&dname=0na&p=%E9%9B%BB%E6%92%83) is the following:

> 電光のように、前ぶれなしに衝撃を与えること。「―的な結婚」

I don't see any particular reason to translate this use of 電撃 to *electric shock* in English.  It's the first gloss listed in some dictionaries, but that doesn't make it the right translation.  The reason many J-E dictionaries list multiple glosses is that, for many words, there isn't a one-to-one correspondence between the two languages.  The best translation for a given term often depends on context.  

How does that apply here?  Well, this is a common metaphoric use of the Japanese word 電撃, but the English term *electric shock* is usually used literally, so we're better off finding another translation.  Let's check some dictionaries:

The Green Goddess gives 電撃結婚 as *a lightning marriage*, so if you want to use a similar metaphor in English, you could phrase it that way.  You can also translate it without relying on metaphor: the same dictionary gives 電撃的 as *sudden and unexpected*, and both the Kenkyusha College J-E and Progressive J-E give 電撃結婚 as *a sudden marriage*.