It’s essentially “D-day” for HTC and its Android-flavored devices here in The States. After weeks of postponing, the ITC (International Trade Commission) has finally made a decision in the Apple vs. HTC patent dispute case.

We told you about the lawsuit earlier this month in which Apple is suing the Taiwanese manufacturer for infringing on four of its patents. The outcome could have a huge impact on both companies. So, what did the ITC decide?

According to The Verge, the ITC has ruled in favor of Apple. Starting April 19, 2012, HTC’s infringing products are banned from being imported into the US. The ruling applies to several products, including Sprint’s Evo 4G, Verizon’s Droid Incredible, and the T-Mobile G2.

Nilay Patel from The Verge has more:

“After a lengthy review, the Commission found that HTC devices infringe two claims of patent #5,946, 647, which is a system level patent issued in 1999 on analyzing and linking data structures—ultimately implicating Android itself and not HTC’s specific implementation. The decision now goes to the desk of the president, who has 60 days to issue a rarely-used veto.”

The news has to be devastating for HTC, who has already reduced its Q4 projected sales for this year due to poor sales. Product sales in the US made up nearly half of the company’s sales last year. But it’s not going down without a fight:

“We are gratified that the commission affirmed the judge’s determination on the ‘721 and ‘983 patents, and reversed its decision on the ‘263 patent and partially on the ‘647 patent. While disappointed that a finding of violation was still found on two claims of the ‘647 patent, we are well prepared for this decision, and our designers have created alternate solutions for the ‘647 patent.”

Not only does the ITC ruling give Apple its first major court victory in its ongoing patent war against Android manufacturers, but it also gives it considerable firepower for future lawsuits. Look out Android partners.