Uhhh, what's this unopened package doing here?

So last night, my friend came over and feeling adventurous, we decided to brew our second batch of beer together. All went seemingly well. I tried doing a bigger boil than the instructions called for--4 gallons instead of 2.5 from reading somewhere that the bigger the boil the better. Was pleased when I was able to cool the wort down to pitching temperature much more quickly than my first attempt. But then, right after I'd pitched the yeast, I saw an unopened packet of powder. DME. Doh!

I left the wort as is, and put the airlock on and it's happily bubbling away right now. My question is, will this negatively affect my beer? And if so, is there anything I can do to fix it?

Pertinent info: Extract kit from my LHBS, a "Seattle Style Bitter". Ingredients as listed on the instructions:
6 lb. Pale Malt Syrup
1 lb light dry malt
1 lb breiss 10L Caramel Malt
1 1/2 oz chinook hops
1 1/2 oz cascade hops
Munton's dry ale yeast


We just spaced off the DME when we added the LME. My OG was ~1.045 which is a good deal lower than the 1.053-1.059 they had in the instructions, which doesn't exactly bode well.

Well, obviously the beer is going to have a lower gravity than planned, but 1.045 is well into the Special Bitter range, and nearly into the ESB range.
The slightly lower gravity will result in a few more IBU's, but I doubt you will be able to taste the difference in bitterness with the amount of hops you are adding
Looks like your going to have a very hoppy beer.

-a.

I wouldn't worry at all, the beer will still taste good, just a bit more hoppy and only slightly less alcohol.

I agree with the others. You can use your leftover DME for yeast starters.

1lb of DME I wouldn't worry about. If this were 3-5lbs, then I would worry. haha

Use it in your next brew to up the OG a little, might want to add the correct ratio of hops to account for the higher OG though.

You have two factors that will raise the IBUs: the larger boil and forgetting the DME. Depending on the timing of the hops, you'll either have a nice Pale or an ESB.

nice, I'm perfectly fine with a pale or esb. Just wish the abv would be a little higher when done.

I'm new at this too, so I'm just going to put this out there and hopefully some one else will give a positive or negative response:

Could you boil the DME in just enough water to dissolve it, boil it long enough to sterilize, cool it and throw it into the fermenter?