Now that we have the final results for fan, players, and media, I would say Tatum has a much better chance to make the team, while Brown has very little chance. Tatum may be fighting with Bam and Sabonis for two of those last three spots, though.
Tatum finished 5th in fan, 5th in players, and 7th in media (with a weighted score of 5.5); while Brown finished 7th in fan, 13th in players, and 11th in media (with a weighted score of 9.5). Since more F/Cs make it than Gs, it seems as though Tatum has the momentum going in while Brown would need a special exception from the coaches to get the nod. You can see the results below:
I thought that Brown might get the nod based on his consistency and continued improvement from year to year, but with the Cs currently 4th in the conference and with so many names ahead of him in the voting, it is going to be difficult for him to beat out so many guys in front of him. Note: I do realize these votes have nothing to do with the actual final selections done by coaches, but I'd have to imagine they at least partially use these results as a barometer for close calls.
Kind of surprised to see Brown ranked #13 among the players. My biased eyes think that's a bit harsh.
Eh, unless you're at the very top (like top 3 or 5 maybe), the player vote tends to mean nothing. If you look at the details you can see a lot of players just vote for their teammates. Details here
PHI - with Harris, Horford, Richardson all getting 13+ votes in addition to Embiid and Simmons.
IND - Warren and Turner both got 15 votes, Lamb got 9, Oladipo got 2, in addition to Brogdon and Sabonis. IIRC IND was an obvious offender last year too.
MIA - at least 5 players towed the company line with Dragic and Herro each getting 5, and Nunn 8, in addition to Butler and Bam. Probably more when you consider the backward math (can only vote for 2 guards and 3 front court, but Miami players were apparently classified as 3 guards and 2 front court on the ballots).
BRK - another offender, with Jordan and Allen getting 13 and 11 votes, and injured Durant and Levert combining for 8, in addition to Irving and Dinwiddie.
Not to say that Boston probably isn't an offender too with Tacko 7 votes, Hayward 6, Kanter 4. Just not as bad as some other teams.