The US now has a 'first-to-file' patent system. Whoever files a patent application first on that idea, maintains the patent application (or continuity), and obtains a patent has the right to keep others from making the technology. There are exceptions for businesses that were making the patented product before the first patent application was filed, but you are not suggesting that fact exists in your case.
Until the patent issues, the patent owner does not have any right/ability to file a patent infringement complaint against someone else making their invention. However, once the patent issues, they can stop you from making their product and, if the claims are the same as the patent application that published, they could sue an infringer for making the patented product before the patent was issued.
Answered on Sep 23rd, 2013 at 8:09 AM