I hate to burst anyone's bubble, but they actually aren't doing anything all that scary.
All this really is is a computer-enhanced form of existing genetic modification; Previously, they would cut and paste genes from existing oraganisms chemically, locating and removing targeted genes indirectly.
What they've done here is take the source DNA and the gene they want to add, loaded them both up onto the computer, and cut and pasted there. The real invention here is the printer that allows the electronicly stored DNA to be produced. As such, this is really only a faster and possibly more precise way to do what we already do.
Now, as we all should know, DNA is not a zip document containg an entire copy of the subject. The best metaphore (be patient for spelling- I'm on explorer at the moment) I have heard is that genes are particularly vauge recipies. It will tell you to mix a cup of flour, some sugar, eggs, and water and other bits, and heat it to 350 for an hour or two. It won't tell you to mix them in a bowl, or to use a convection oven rather than a microwave or a toaster.
In life, the chemistry, radiation, temperature, and physical shape of the cell the DNA is in can all have effects. Mitocondria (Midiclorians except instead of giving you the force, they process sugar) come in a number of flavors. Identical twins can come out of the womb looking different, and clones even more so.
To quote from a respected researcher; "Remember, genes are NOT blueprints. This means you can't, for example, insert "the genes for an elephant's trunk" into a giraffe and get a giraffe with a trunk. There -are- no genes for trunks. What you CAN do with genes is chemistry, since DNA codes for chemicals."
Or, to give an example we might be familiar with; genes are like seed numbers for a DF world. Used in the same copy, they'll generate similar worlds. But used in a different environment (different OS, hardware, or DF version), the result can be very different.
Still, great work Vester. Keep it up.