I don't see it as a big "oh noes" that the titles are not defended at Wrestlemania, certainly it would put on a good match, but currently as it looks on the card, Drew McIntyre wouldn't have had any worthy contender to fight against, seeing as the only people that could probably get somewhat of a title shot at this moment is either already in the MITB match, or in a tag team (Cryme Tyme and Hart Dynasty)
And The Miz wouldn't be able to defend his US title that night because he's defending the Unified Tag Team titles, which gives another person a spot at Wrestlemania: Big Show.
Besides, removing the tag team match or lowering the amount of people in the MITB match, would certainly give more contenders for the titles, but it would add yet another match at Wrestlemania, coming to the amount of 9 matches, one more than last year, but oh wait, thats right, people are complaining that one of the matches was a dark match, and another one was short as hell.
Therefore, one tag team match, and a big MITB would make more sense and keeping the amount at 8 matches, which will still most likely have one match as a dark match, and another short match to allow the bigger matches to continue longer.
And to add that, no, I don't really wanna see the titles unified, not even on a short period, because I already feel that WWE has too few titles for the amount of wrestlers they have that could be doing a proper title feud rather than a small meaningless match for the sake of entertainment, cause lets face it, thats probably the only thing Evan Bourne for example has been doing before he qualified for the MITB.