3Dcenter is quite reliable and they have their sources with some of the graphic card vendors, so I believe this (at least the Fiji spec) to be decently reliable.
3DCenter via Videocardz
Bing translation of the table (Right column labelled source of information is)
1. General thinking in 3dcenter forums for 395X2
2. Graphics cards = Information from Graphics card manufacturer
3. Own speculation = well own speculation
4. VR-Zone rumor
Radeon R9 395X2 Bermuda
Starting with Bermuda. You probably heard this name before, but no one was certain if Bermuda is the actual flagship GPU or something else. Well as a matter of fact Bermuda could actually be the Vesuvius successor (R9 295X2). Radeon R9 395X2 would be a direct competitor to rumored GTX 990 (likely dual-GM204).
Radeon R9 390(X) Fiji
According to 3DCenter, Fiji is confirmed as next flagship GPU. The R9 390X will likely be powered by Fiji XT, whereas R9 390 with Fiji PRO. Fiji-powered graphics cards are said to be the first with High-Bandwidth-Memory on board. NVIDIA will possibly adopt HBM with Pascal, so we are looking at months, or maybe even years, of AMD leadership in this technology.
Radeon R9 380(X) Grenada
I think it was quite obvious Hawaii, which was released in late 2013, would not be forgotten in upcoming 300 series. The rumor has it that Hawaii will be renamed to Grenada. Does it mean architectural changes? Likely not, but we expect Grenada to be more power efficient, and configured with higher clock speeds.
Radeon R9 370(X) Tonga
Tonga was first released with Radeon R9 285. AMD had plans to release R9 285X (this is not a rumor), however due to GTX 970 announcement, those plans had to be changed. The full Tonga is actually equipped with 384-bit interface, so R9 370X should launch with 3GB on board. We are looking at potential GM206 competitor here.
Radeon R7 360(X) Trinidad
Trinidad is Curacao (Pitcairn) replacement expected to launch with Radeon R7 360 series. The only information we have is limited to memory configuration of 256-bit and 2GB frame buffer. Additionally, Trinidad may be the first card of Radeon 300 series, as its currently planned for March (according to VR-Zone).
3DCenter via Videocardz
Bing translation of the table (Right column labelled source of information is)
1. General thinking in 3dcenter forums for 395X2
2. Graphics cards = Information from Graphics card manufacturer
3. Own speculation = well own speculation
4. VR-Zone rumor