A traditional panel from the last two Star Wars Celebrations is missing this year, which means Han Solo won’t get the spotlight.
The previous two Celebrations featured a “Future Filmmaker’s Panel”. At Anaheim we learned about Rogue One and how Josh Trank likely wouldn’t be involved with Star Wars anymore. Then in London they covered Han Solo a little bit with the directors and Han himself. This year that panel is not on the official schedule for the convention meaning they’re skipping it and anything big that will be announced could be done during the 40th Anniversary panel.
Current rumor says Disney is holding off on Han Solo stuff until the D23 Expo in July. While it’s likely we could get the title before then, if for some reason that doesn’t happen it’s expected that they’ll reveal the title and possibly even more at Disney’s presentation.
The D23 Expo is every two years, and they tend to show things very far out there. Two years ago they showed the first footage for Pirates 5, which is out this May. With Han Solo currently due in May of 2018, it’s even possible they may show some kind of behind-the-scenes clip at D23.