A little utility called Safari Enhancer also added a New Tab button, it's stopped working with Safari 3, hopefully it will be updated soon. You can also change the Google Search bar to regional ones like Google UK etc. Very useful.
Unfortunately, probably not. The developer has stated in his forums that he will not continue updating and developing Safari Enhancer anymore due to personal reasons / life.
I do hope that Apple will finally implement this feature. All the other browsers have it, why not Apple.
I really like and prefer Safari. But, why must we sacrifice something so simple that really should be built-in.
I have submitted my request to Apple for them to implement the feature in upcoming releases. Hopefully they'll comply and activate this simple little button for us.
If you want to request it yourself, go ahead. I would encourage everyone to request this feature (and any other feature you would like). If enough people request a given feature, then maybe Apple will see that it is worth their time to add it.
You can request features and changes on Apple's website at:
http://www.apple.com/feedback/
There is not a direct button to suggest improvements to Safari. Instead, choose to give feedback on OS X. Then, in the box for "Feedback Area" choose "Internet/Web"
For "Feedback Type", I chose design / ease of use. But, efficiency/workflow would probably be suitable from a certain perspective. It's most likely suited to design / ease of use though.
Anyway, I encourage everyone to give feedback and suggest features for anything you would like. I drop by there an request features or changes to computers, OS X, and anything else whenever something I'm doing doesn't seem to be handled right, or if I see a lack in what I'm using.