Capcom have indirectly registered a domain for Devil May Cry 5 on 18 May 2018, almost a month before E3 2018. Normally, this wouldn't mean much, but sources show that "devilmaycry5.com" dedicated servers were configured on 01 June 2018.
Sleuths at ResetERA have caught wind of the domain registration, with The Palemoon discovering it initially and MH MD following up with a full blown investigation. After learning of the registration, MH MD delved deeper to see if the info checks out, eventually discovering that the company who registered the domain was GMO Internet Inc.
The company is apparently a legitimate ISP in Japan, and they were affiliated with Capcom on several occasions in the past. GMO Internet Inc. also registered monsterhunterworld.com, residentevil7.com and residentevil2.com. All of these domains were registered shortly before the games were announced.
For example, Monster Hunter World's domain was registered on 28 April 2017 and the game was announced on E3 2017 which took place from 13 to 15 June 2017. Devil May Cry 5 domain was registered on 18 May 2018 which sets the game up for an announcement on E3 2018.
Furthermore, several users on ResetERA have confirmed that they get the same message simply stating "OK" when they visit devilmaycry5.com which was also the case with residentevil2.com for a while now, testifying further for the legitimacy of Capcom's new site.
Now to address the scariest question of them all - will we get the original Dante or the one from the 2013 reboot. Unfortunately, there won't be any official info before E3 2018 but considering the game is called Devil May Cry 5 and not DmC: Devil May Cry 2, it is safe to say we will get the cocky demonic version of Deadpool instead of the slightly more broody 2013's social outcast.
Capcom have announced a Resident Evil 2 remake back in 2015 but they didn't reveal any details about it yet, which leaves even more room for possible surprises during Capcom's E3 2018 conference.