Shortly after hinting his website could be back online in the coming months, he also tweeted: Yes... Megabox is also coming this year ;-)".
Megabox is a site that would allow artists to sell music direct to users, the TNW website reported.
Dotcom said it would "unchain" consumers from the music industry.
Police raided the German millionaire's mansion in January and seized his assets after the US asked for assistance under an international agreement.
The website, which had carried 4 per cent of internet traffic, was closed down.
He was arrested, along with three other executives of the Megaupload site and were charged with criminal copyright violation through his Megaupload website.
They have all said they will fight the charges.
A High Court decision has since ruled the raid illegal because it was based on invalid search warrants.
A hearing into his extradition to the United States is due to be heard next March.
A judgement released this week by chief High Court Judge Justice Helen Winkelmann said at the hearing the FBI would have to prove it had the evidence to back up its charges.