Unfortunately, no. Your best bet would be to let him browse the forums/catalogue, enjoy the free games he gets by sigining up, and should he mention a few he likes, send him one of those.

That's a badass idea, but I'm not sure it's possible.

This is one of several wish list requests to enhance gifting on GOG:

http://www.gog.com/wishlist/site/gog_gift_card_redeem_1_or_more_games_of_599999xxx_value

Given that GOG can provide open ended gifts, I have to believe they aren't too far from being able to let us purchase those exact same things for others.

That said, none of the wishes are "in Progress" and the one linked has over 400 signatures. Perhaps GOG just needs an.. "AHEM!" from us :p

Open ended gifts? You mean the bonus codes?
My guess would be that they are a logistical nightmare. How/when does GOG pay the publisher? Does it get the $9.99 when you buy the bonus code, then it pays the publisher its cut when you use it? What happens with the money logbook, especially if the purchase and redemption are on different fiscal years? Do they also make the bonus codes last indefinately or have them with an expiration date as they currently are?
So as much as I do like the bonus codes, it does seem as if it's a bit more complicated than we think :(

I think you might be over-thinking it? or better asked, how is everyone else able to accomplish this? Steam would have to work out the same questions. So would Gamestop, Apple, Amazon... No need to reinvent the wheel here.

I"m guessing it isn't as simple as flipping a switch, else they would have done it by now... but I also think its extremely doable. (especially with the proven track record for gifting on this site... people have long past put their money where there mouth is in that regard)

Well, yeah. Currently you can't do that on GOG. Just tell your friends you want to gift him something from GOG with certain value, let your friends browse the game, and buy it.

Nearly all of those concerns are fairly easy to handle from an accounting/bookkeeping perspective if GOG follows anything remotely close to GAAP accounting principles. I understand that the specifics of the accounting regulations that they are subject to may differ, but I'd be surprised if they did so in a substantial way. Upon receiving the payment for the bonus code, GOG would book that as revenue with an attendant payables journal entry. They would then pay the appropriate publisher upon redemption of the code (assuming that there was no expiration date on the code) and reconcile the journal entry. If there is an expiration date and the code goes unredeemed, they keep the revenue and again reconcile the payable journal entry.

Again, assuming that they are accounting near-GAAP the year-to-year carryover is a matter of making an accrual based on what they feel is the likelihood or purchase/redemption occuring in differing accounting periods.

Now, all that said, there may be other business considerations that prevent the offering of generic codes. But I can't see why accounting would be an insurmountable obstacle.

...and now aside from your "hobby" i mentioned elsewhere you will now be inundated with peoples tax concerns! Heheh! ;)

Lord, I hope not. Anyone coming to me for tax advice would be doing so to their detriment. :-)