company buy-outs/merges and paychecks

This is a good question, but I do not think you have anything to worry about. Mergers take time to be effectuated, and while changes are certain to come, your employment should not be effected - at least as far as taxes are concerned.

Typically in a merger, the companies involved in the transaction will form a new company or operate as the old entities. In your situation, the purchased company may have a better marketing face, client base or other intangible quality that made it an attractive purchase. Likely, the second half of last year was spent closing the deal, tidying paperwork and establishing a business plan.

Mergers are generally put into effect for the beginning of a new year, for obvious tax reasons. Because you were paid from the former company throughout 2008, you will only have 1 W2 to file. The same will hold for this year, as the new company name will show on the W2. But alas, the company is the same entity, just formed in a different manner.

Because the company has merged under the guise of the purchased company, your W2 will likely feature the employer tax number of the final merged entity.

There should be no tax issues of which you should be concerned. Enjoy the new business guise. Here is a good article about the reasons companies merge and the fears and successes enjoyed by such mergers - http://findarticles.com/p/articles/mi_m0DTI/is_n11_v25/ai_20172810.

Many taxpayers are worried about the pending buy-out proposal. However, I wouldn't worry about that or anything in your scenario. You do not need to fill out another W-4 unless your information has changed.