h4 visa stamping prior to h1b start date

[inamgift]

I am currently on OPT but my h1b visa got approved and it starts from jan 1st 2010. Is it possible to go for dependent h4 visa stamping by my wife now in october month(prior to start date).

[kabkaba]

I assume you mean Jan 1, 2011 and not 2010.
Your wife can apply now, but she will not be able to travel before the effective date. Alternatively she can get F2 Visa and then file for COS to H4 after coming to US before Jan 1.